Edited by Jürgen Basedow, Giesela Rühl, Franco Ferrari and Pedro de Miguel Asensio
Chapter N.2: Nationality
I. Concept and notion
1. Nationality and citizenship
The term ‘nationality’ carries two meanings. First, ‘nationality’ describes the formal legal belonging of a natural person to a p. 1290state. In this meaning, it is synonymous with the term ‘citizenship’ (Staatsbürgerschaft, Staatsangehörigkeit; citoyenneté; cittadinanza; cidadania; ciudadanía). A condition for the formation and existence of a state is the existence of people of a polity (or state) – that is, citizens. Citizenship of a state carries certain rights and obligations between the citizen and the state with it; in democracies, for example, one instance of this is the right to vote. Second, ‘nationality’ can also describe the belonging of a person to a ‘nation’ (derived from the Latin term natio). In this meaning, ‘nation’ can be understood as a collective of people of a shared cultural and historic origin and, often, of a common language. The meaning of the term is not defined by reference to the notion of ‘state’; rather, it is an anthropologic notion. In the case of a ‘nation state’, the two groups ‘nation’ and ‘people of the polity (or state)’ overlap completely.
In modern private international law and international procedural law, ‘nationality’ always refers to the formal legal status of citizenship. Thus the terms ‘nationality’ and ‘citizenship’ are used synonymously with this meaning from here on, unless indicated otherwise.
2. Meaning in conflict of laws
In conflict of laws, the use of nationality as a connecting factor is called the ‘nationality principle’. The natural person’s nationality is used as a connecting factor to determine predominantly the law applicable to the →personal status (see II.). The law of the state of a person’s citizenship is also called ‘lex patria’ (national law). For example, art 37(2) Swiss Private International Law Act (Bundesgesetz über das Internationale Privatrecht of 18 December 1987, 1988 BBl I 5, as amended) states: ‘A person can nevertheless demand that his name is governed by the laws of its home state.’ Citizenship plays a limited role in international procedural law (see VII.). For example, art 8(c) →Rome III Regulation (Council Regulation (EU) No 1259/2010 of 20 December 2010 implementing enhanced cooperation in the area of the law applicable to divorce and legal separation,  OJ L 343/10) – albeit only subsidiarily – renders the law of the state ‘of which both spouses are nationals at the time the court is seized’ applicable in the event of a divorce (→Divorce and personal separation). At the same time, according to art 3(1)(b) →Brussels IIa Regulation (Council Regulation (EC) No 2201/2003 of 27 November 2003 concerning jurisdiction and the recognition and enforcement of judgments in matrimonial matters and the matters of parental responsibility, repealing Regulation (EC) No 1347/2000,  OJ L 338/1), jurisdiction in matters relating to divorce, legal separation or marriage annulment shall lie inter alia with the courts of the Member State of the nationality of both spouses. A dichotomy exists between the use of citizenship on the one hand and the use of spatial connecting factors such as residence or domicile on the other. Generally, citizenship does not play a major role as a →connecting factor in common law jurisdictions. Traditionally, at common law, ‘domicile’ is used as the connecting factor rather than citizenship (→Domicile, habitual residence and establishment). Thus, in EU law, art 3(1)(c) Brussels IIa Regulation provides a →substitution. In the case of the →United Kingdom and →Ireland, the aforementioned international jurisdiction in divorce matters of the courts of the state of the spouses’ common nationality is replaced by the jurisdiction of the courts of the state of common domicile. For the purpose of the regulation, ‘domicile’ has the same meaning as it has under the legal systems of the United Kingdom and Ireland (art 3(2) Brussels IIa Regulation).
In most legislations, nationality is used as a connecting factor in the form of multilateral conflict rules. In this way, the different legal systems are treated equally in conflict of laws. Unilateral rules that combine the nationality principle with the use of residence as a connecting factor in cases of domestically-resident aliens (eg art 1195(1), (3) Civil Code of the Russian Federation (as amended by Federal Law No 260-FZ on 30 September 2013)) are a rare exception. This is because such unilateral connections go against the conflict-of-laws principle of equal treatment of legal systems.
3. Acquisition and loss of citizenship
Each state decides under which conditions its citizenship is acquired (Case C-135/08 Rottmann v Bavaria  ECR I-1449, para 39; art 3(1) Strasbourg European Convention p. 1291on Nationality of 6 November 1997 (ETS No 166)). Thus, any issue of family law raised in the proceedings leading to the conferral of citizenship by a country must be resolved as it would be by the courts of this state. This means that incidental questions (→Incidental (preliminary) question) relating to family law are to be resolved by referring to the laws of the legal system which has already been selected to govern the principal issue. This includes the foreign conflict-of-laws rules.
General public international law only rarely limits states’ authority to shape their citizenship laws. In the Nottebohm case (Liechtenstein v Guatemala (1955) 1 I.C.J. Rep 4, para 24 ff), the ICJ held that a person can only be considered a citizen of a certain state if he has a factual, genuine link to this state. However, the threshold for meeting the conditions of such a genuine connection is very low. The decision was rendered in the field of diplomatic protection; whether it contains a general rule of law is open to debate. At any rate, the decision has no impact on the conflict of laws.
Every national of a Member State also has EU citizenship (art 20 TFEU (The Treaty on the Functioning of the European Union (consolidated version),  OJ C 326/47)). This allows the CJEU to review the compatibility of Member States’ citizenship laws and of their application; for example, the Court reserves the right to check whether the denaturalization of an EU citizen is proportional and legal (Case C-135/08 Rottmann v Bavaria  ECR I-1449, para 45, 55 ff). The ECtHR checks whether the national citizenship laws of an ECHR Member State are consistent with ECHR requirements – for example, if, in citizenship law, children born in wedlock are treated the same as those born out of it (Genovese v Malta, no 53124/09 (ECtHR, 11 October 2011)), or whether men and women are treated equally.
Some bi- or multilateral treaties stipulate requirements regarding national citizenship law in order to prevent results such as multiple citizenship, statelessness, or discrimination against married women (see the UN Convention of 29 February 1957 on the nationality of married women, 309 UNTS 65). According to this convention, for women, marriage entails neither a loss of citizenship, nor the ipso iure acquisition of the husband’s citizenship. Rather, as a general rule, it creates a right to naturalization in the spouse’s country of citizenship. The Strasbourg European Convention on Nationality of 6 November 1997 (ETS No 166) favours multiple citizenship in various cases.
Citizenship is acquired by virtue of law or through a sovereign act (for an overview: Oliver Dörr, ‘Nationality’ in Rüdiger Wolfrum (ed), Max Planck Encyclopedia of Public International Law (OUP 2012) paras 11 ff, 18 ff; Olivier Vonk, Nationality Law in the Western Hemisphere (Brill/Nijhoff 2014) 3 ff, 384 ff).
a) Acquisition by birth
The most important reason for acquisition is acquisition by birth ex lege. Two principles of acquisition by birth can be distinguished: the ius soli and the ius sanguinis principle.
(1) Acquisition by virtue of birth within state territory
According to the ius soli principle, birth within a state’s territory confers the citizenship of that state to the person born. The ius soli principle is prevalent in Latin America and Anglo-Saxon countries. Generally, it is more common in traditional immigration countries because, starting from the second generation of immigrants, it leads to a greater congruity of resident population and people of the polity.
(2) Acquisition by virtue of birth through descent
The second principle is the principle of ius sanguinis, which still prevails in continental Europe. According to this principle, citizenship is conferred by descent from a citizen. Countries that were traditional emigration countries at the beginning of the 20th century prevalently follow the ius sanguinis principle. Some of these countries, which have by now become immigration countries, have complemented their citizenship laws with variations of ius soli acquisition rules. One example that comes to mind is Germany, which reformed its citizenship laws in this sense in 2000 and further extended its citizenship laws in 2014. Nowadays, the equal treatment of women and men in nationality law is the international standard. But up until the middle of the 20th century, only the father could confer citizenship on the child. Today this is the case in only a few countries, particularly those influenced by Islamic law (eg Abu Dhabi, Bahrain, Oman, →Saudi Arabia, Senegal, Somalia, Syria and the United Arab Emirates). In some countries which follow the ius soli principle, citizenship is conferred by patrilineal descent alone in the event of births abroad (eg the Bahamas, p. 1292Barbados, →India, →Iran, Jordan, Kuwait, Lebanon, Liberia and Niger).
b) Acquisition ex lege on other grounds
→Adoption, legitimation, →marriage and other changes in the civil status of a natural person can lead to the acquisition of the citizenship of a state to which another person – for instance, the adopting party or spouse – belongs. But according to modern conventions (see for example UN Convention of 29 February 1957 on the nationality of married women), for women, →marriage or divorce (or other dissolution of marriage; →Divorce and personal separation) entails neither a loss of citizenship, nor the ipso iure acquisition of the husband’s citizenship (same rule for both spouses: Strasbourg European Convention on Nationality of 6 November 1997). Rather, as a general rule, it creates a right to naturalization in the spouse’s country of citizenship.
c) Acquisition by naturalization
Citizenship can also be awarded through a sovereign act (naturalization). Nowadays, the laws of many nations recognize the right to naturalization of spouses, registered partners, or children of their citizens; the right to naturalization of domestically-born foreigners may also be recognized if certain further conditions are met. Within the EU, the possibility of dual citizenship of two Member States is promoted. In some countries, the acquisition of citizenship a declaration addressed to the relevant state (eg in the event of aliens born inside that state) is equivalent to naturalization.
Loss of citizenship can occur through a sovereign act (denaturalization by legislative act, administrative act or – rarely – judicial act of state) or by operation of law. According to customary international law, no one shall be arbitrarily deprived of his nationality (see also art 15(2) Universal Declaration on Human Rights of 10 December 1948, Resolution 217 A (III) General Assembly (1948–49) U.N.Y.B. 535; see Oliver Dörr, ‘Nationality’ in Rüdiger Wolfrum (ed), Max Planck Encyclopedia of Public International Law (OUP 2012) paras 32 ff). Nowadays, only a few countries provide for a loss of citizenship in the event of marriage to a foreign spouse; this is particularly common if the citizen in question is a woman (for example, with varying other requirements, according to the laws of Afghanistan, the People’s Republic of →China, →Indonesia, →Iran, the Republic of →Korea (South Korea), Kuwait, Libya, Madagascar, etc.).
4. Citizenship of tangible movables and legal persons
Public international law sometimes makes reference to the concept of ‘nationality’ of legal persons. Similarly, nationality is also ascribed to tangible movables, particularly ships and aircraft (see on this point Oliver Dörr, ‘Nationality’ in Rüdiger Wolfrum (ed), Max Planck Encyclopedia of Public International Law (OUP 2012) para 24). Pursuant to art 17 of the Convention of 7 December 1944 on International Civil Aviation (15 UNTS 295), aircraft have the nationality of the state in which they are registered. In private international law, some jurisdictions explicitly use the nationality of means of transport as a connecting factor. For example, art 45(1) no 1 of the Introductory Act to the German Civil Code (Einführungsgesetz zum Bürgerlichen Gesetzbuche of 21 September 1994, BGBl. I 2494, as amended, henceforth EGBGB) provides that interests in aircraft are governed by the law of the country of origin. This is the country of the aircraft’s nationality. The rules that govern the nationality of legal persons and mobile assets such as ships are very different from those that govern natural persons. This entry deals only with the latter.
II. Purpose and function
1. Personal status
Private international law sees citizenship as the →connecting factor predominantly to determine →personal status. The term ‘personal status’ has different meanings (Heinz-Peter Mansel, Personalstatut, Staatsangehörigkeit und Effektivität (CH Beck 1988) 42–3). One of these meanings is to refer to the law that governs certain legal questions intrinsically linked to a person, such as personal law (name, legal capacity (→Capacity and emancipation) and contractual capability etc), family law or the law of successions.
In many states, personal status is determined by a person’s domicile or habitual residence; in others, nationality is used as the connecting factor (see I.2., IV.). The nationality principle was not developed as a means of indicating the applicable law in matters relating to personal status until the 19th century. Nowadays, it is p. 1293explained by referring to four arguments, which are widely used in legislative materials, doctrine and case-law. These different legal policy accounts are not mutually exclusive; instead, they complement one another. They have different strengths and weaknesses. Based on factors such as the historical state of the legislator at the time the rule was postulated, or the percentage of alien residents, one reason or another will be more important to the legislator. In liberal democracies, justification by reference to a democratic theory might be of importance (see II.4.). In non-democratic states, on the other hand, the legislator’s decision to follow the nationality principle is more likely to be based on considerations of state sovereignty over their subjects, given that the individual is seen less as an autonomous person and more as an object of the law (see II.3.) In societies with a homogenous resident population and a low percentage of foreigners, justification by reference to cultural identity is accorded greater weight (see II.2.). Pragmatic arguments are commonly used (see II.5.).
2. Closest connection of a person to a state
The nationality principle is still being justified by referring to the hypothesis that, in an ideal situation, the law to which a person has the strongest link is the law of his nationality. This is because, from a generalized perspective, nationality documents a lasting, personal link between persons and the state whose citizenship they hold. Its laws are the ones which the national knows best (Federal Constitutional Court of Germany (BVerfG), 18 July 2006,  IPRax 217, 222 ff; see Heinz-Peter Mansel, ‘Die kulturelle Identität im internationalen Privatrecht’ in Georg Nolte and others (eds), Pluralistische Gesellschaften und Internationales Recht (CF Müller 2008) 137, 156 with further references). This state is thus generally called the ‘home state’. According to the doctrine of conflict interests established by Gerhard Kegel (→Kegel, Gerhard) the use of nationality as a connecting factor respects the continuity interest of the person in question. They are permanently subject to the same personal laws, regardless of location or jurisdiction (Alexander Lüderitz, ‘Anknüpfung im Parteiinteresse’ in Alexander Lüderitz and Jochen Schröder (eds), Internationales Privatrecht und Rechtsvergleichung im Ausgang des 20. Jahrhunderts. Bewahrung oder Wende? Festschrift für Gerhard Kegel (Metzner 1977) 31, 33 ff).
Erik Jayme in particular argues for the existence of the subjective right, based on human rights (→Human rights and private international law) and constitutional rights, to the recognition of the cultural identity of the individual, which is shaped by the common history and culture of all citizens of a state (Erik Jayme, ‘Identité culturelle et intégration: le droit international privé postmoderne’ (1995) 251 Rec. des Cours 9, 11 f, 167 f; see also Hélène Gaudemet-Tallon, ‘Nationalité, statut personnel et droit de l’homme’ in Heinz-Peter Mansel and others (eds), Festschrift für Erik Jayme (Sellier European Law Publishers 2004) 205 ff; Yuko Nishitani, ‘Global Citizens and Family Relations’  ELR 134, 137). The concept of basing the nationality principle on the notion of cultural identity has found increasing acceptance in the scholarly community. The Institute de Droit international, in its resolution of 25 August 2005 on ‘Différences culturelles et ordre public en droit international privé de la famille’ ((2006) 71:2 Annuaire de l’Institut de Droit international 291, 292,  IPRax 559, 560; Rapporteur: Paul Lagarde), has recognized the use of nationality as an expression of the law’s cultural orientation, but has also proposed giving a person the right to choose between the laws of his home state and the laws of his domicile state.
This justification of the nationality principle by reference to the person is a genuine private law justification. Thus, it is appropriate to the conflict of laws. However, it has the disadvantage of only being appropriate in ideal cases. In mobile societies, a large percentage of residents can be foreigners who have become alienated from their home jurisdiction and are now rooted in the legal order of their host state. The interest to adapt – leading to an application of the laws of residence – can thus outweigh the aforementioned continuity interest (see Alexander Lüderitz, ‘Anknüpfung im Parteiinteresse’ in Alexander Lüderitz and Jochen Schröder (eds), Internationales Privatrecht und Rechtsvergleichung im Ausgang des 20. Jahrhunderts. Bewahrung oder Wende? Festschrift für Gerhard Kegel (Metzner 1977) 31, 33). On the other hand, in large, culturally diverse societies, greater groups of foreigners might exist in which the continuity interest outweighs the adaption interest, for example because they live in the host state as immigrants p. 1294for economic reasons or for a limited period of time as skilled workers, and continue to have stronger ties to their origin state than to their host state. In certain circumstances, this could also affect second- and third-generation immigrants (for numbers on the impressive share of first- and second-generation migrants within the resident population of European countries see Eurostat, European Commission, Migrants in Europe: A Statistical Portrait of the First and Second Generation (2011)). Nowadays, thanks to modern means of communication, keeping ties to one’s home society has become much easier.
3. Sovereignty over subjects and state sovereignty
A second line of reasoning is based on state interests. The use of nationality as a connecting factor protects the state’s sovereignty over its subjects as well as home state sovereignty. Furthermore, the nationality principle respects the sovereignty of other states, as well as the independence of those states’ legal systems (Federal Constitutional Court of Germany (BVerfG), 18 July 2006,  IPRax 217, 222 ff). The UN Administrative Tribunal (Adrian v The Secretary-General of the United Nations, Judgment No 1183, Case No 1276 dated 30 September 2004) points to cultural identity, but particularly to state sovereignty with regards to the shape of the state’s own legal order when justifying the nationality principle. The application of the lex patria to questions relating to an individual’s personal status respects the cultural and religious diversity of different legal systems. In the Adrian decision, this principle became relevant in the context of the recognition of →same-sex marriages by the UN. The tribunal held that the question as to whether or not a UN civil servant had certain spousal benefits if both spouses are men depended on the recognition of this marriage by the home state; it should be noted that the UN has reversed its administrative policy and now recognizes any same-sex marriage that was valid according to the laws at the place it was entered into. The UN tribunal also emphasized the point of state sovereignty protection through this measure.
This line of reasoning is based on considerations of public law alone, referring to the state only. It takes a state-centric approach and neglects the specific conflicts interest: determination of the applicable law with which the person has the closest connection in the interest of this person. It might have more importance for a UN court because of its deference to the interest of the UN member states.
Reversely, the nationality principle in conflict of laws cannot be justified by the assumption that a citizen living abroad has a right against his host state to ensure the application of his home laws in personal matters. This right does not derive from general international law. Presumably, it is unknown to most national constitutions; at any rate, it does not derive from the general equality principle. The determination of an individual’s personal status by his nationality, habitual residence or domicile is not a function of human rights (on this see Heinz-Peter Mansel, ‘Die kulturelle Identität im internationalen Privatrecht’ in Georg Nolte and others (eds), Pluralistische Gesellschaften und Internationales Recht (CF Müller 2008) 137, 156 with further references) (→Constitutional law and private international law).
4. Open societies and democratic participation
Modern liberal-pluralistic democracies are shaped by their constitution and the idea of human rights. Constitutional patriotism replaces a common culture shared by all members as the link between state and polity (constitutional patriotism as described by Dolf Sternberg and expanded to include the political idea of the EU by Jürgen Habermas, ‘Citizenship and National Identity’ in Bart Van Steenbergen (ed), The Condition of Citizenship (Sage 1994) 20 ff; for constitutional patriotism in civil society see Jürgen Habermas, Faktizität und Geltung (Suhrkamp 1992) 633 ff). This approach might be more suitable for explaining the new orientation of Western mobile societies open to immigration than merely culturally determined concepts. This also gives rise to another basis of legitimacy for the nationality principle. It means that private law is made by parliaments. The right to elect the parliament is tied to citizenship in most countries on earth. In an idealized, ordinary situation, the possibility of influencing law through political participation in parliamentary elections allows citizens to identify themselves with the laws of their country and to accept them as their own laws (Heinz-Peter Mansel, ‘Die kulturelle Identität im internationalen Privatrecht’ in Georg Nolte and others (eds), Pluralistische Gesellschaften und Internationales Recht (CF Müller 2008) 137, 165–6).
p. 1295But nationality is used as a connecting factor regardless of the right to vote; people lacking the right to vote are subjected, with regards to personal status, to the laws of their home state as well. Claims have been made that the element of potential political participation is fictitious (see inter alia Louis d’Avout, ‘La lex personalis entre nationalité, domicile et résidence habituelle’ in Mélanges en l’honneur du Professeur Bernard Audit (L.G.D.J. 2014) 17, 22 no 13; Yuko Nishitani, ‘Global Citizens and Family Relations’  ELR 134, 138). However, the democratic theory argument does not depend on the concrete influence of voting decisions on the legal system. Rather, the opportunity of political participation in modern, democratic-liberal and culturally divergent societies appears to be a suitable and rational means of establishing a connection between a person and the legal order of a state. Against it, it is argued that there are no elections in many of the states which follow the nationality principle. In these states, the connecting factor is mostly based on a different foundation, state sovereignty being the most common. For democratic states, the constitutional state of active citizens remains a valid legal policy model for the use of nationality as a →connecting factor (see Heinz-Peter Mansel, ‘Die kulturelle Identität im internationalen Privatrecht’ in Georg Nolte and others (eds), Pluralistische Gesellschaften und Internationales Recht (CF Müller 2008) 137, 165–6).
5. Legal certainty and pragmatism
Use of nationality as a connecting factor can be justified by referring to pragmatic reasoning. In regular cases, nationality is more secure and easier to determine than domicile or habitual residence (→Domicile, habitual residence and establishment). Due to the fact that nationality cannot be changed quickly, manipulation of the connection is not as easy as it would be if (habitual) residence were used. Thus, while it is still a connecting factor which is subject to change, it creates fewer changes of applicable law (see The Law Commission and The Scottish Law Commission, Private International Law: The Law of Domicile (Law Com No 168, 1987, Scot Law Com No 107, 1987) para 3.9). On the other hand, use of nationality as a connecting factor leads to an increased application of foreign laws in a heterogeneous society. This, in turn, leads to a more difficult application of the laws and an increase in costs of determining the content of foreign laws. It might also result in triggering the ordre public more frequently.
III. Historical development
The nationality principle was not developed in Continental Europe as a means of indicating the law applicable in matters relating to personal status until the 19th century. At that time, the political purpose of citizenship was a central topic. The state’s sovereignty over its subjects gained importance; thus, to the legislators of the national statutes that evolved during the 19th century, subduing all of their citizens under their laws seemed legitimate. For them, this was an expression of state sovereignty. The French Civil Code (Code Civil of 21 March 1804; henceforth French CC) (in art 3(3)) followed by the Austrian Civil Code (Allgemeines Bürgerliches Gesetzbuch of 1 June 1811, JGS No 946/1811, as amended) (in art 4, 34) began this trend by stipulating unilateral conflict-of-laws rules for their own nationals. The civil code of the Kingdom of Saxony of 1863 (in § 7 Bürgerliches Gesetzbuch) and the Italian Codice civile of 1865 then introduced the multilateral use of nationality as a connecting factor. The Italian civil code was based on the works of Pasquale Stanislao Mancini (1817–88; →Mancini, Pasquale Stanislao). His famous speech of 1851 about nazionalità as the foundation of international law (‘Della nazionalità come fondamento del dritto delle genti: prelezione al corso di dritto internazionale e marittimo pronunziata nella R. Università di Torino nel dì 22 gennaio 1851’ in Pasquale Stanislao Mancini, Diritto internazionale (Marghieri 1873)) is considered to be the theoretical underpinning for the success of the use of nationality as a connecting factor in 19th-century private international law (Erik Jayme, ‘Identité culturelle et intégration: le droit international privé postmoderne’ (1995) 251 Rec. des Cours 9, 174 f). Mancini put private international law on an international law foundation. He viewed the use of nationality as a connecting factor as an expression of the state’s responsibility for its citizens. The Institut de Droit international – established in 1873 by Mancini and Johann Caspar Bluntschli – recommended the use of nationality as a connecting factor in its resolutions. The national legislators of →Spain, →Portugal, →Hungary, →Romania, →Sweden, →Turkey, the →Netherlands, →Japan, →China, →Chile, →Colombia, →p. 1296Peru and →Venezuela followed this recommendation (Heinz-Peter Mansel, Personalstatut, Staatsangehörigkeit und Effektivität (1988) 25 ff), but the principle was not fully adopted in all jurisdictions. For example, French conflict of laws – and, after it, the legal systems that were based on French law – provided for the use of domicile as a connecting factor with regard to questions relating to the laws of →successions and →matrimonial property. The later codification of German private international law (the EGBGB of 18 August 1896 (RGBl. 604), which entered into force on 1 January 1900) used nationality as the sole connecting factor and replaced the domicile principle, which had previously been in place throughout almost all parts of Germany. Further codifications during the first half of the 20th century (eg the Greek conflicts codification of 1940 and the Italian codification of 1942, as well as codifications in Finland and Poland) used nationality as a connecting factor for determining personal status. Twenty-first-century codifications followed (eg Japan, the Republic of Korea (South Korea), the Republic of China (Taiwan) etc, see Yuko Nishitani, ‘Gobal Citizens and Family Relations’  ELR 134, 137). It is worth noting that the Asian countries listed here have only a small percentage of foreigners among the resident population (Yuko Nishitani, ‘Gobal Citizens and Family Relations’  ELR 134, 137). Throughout the common law world, the Scandinavian legal family, the laws of →Estonia and →Latvia in the Baltic states, and →Switzerland, nationality has never achieved significant importance (see the overview in Louis I de Winter, ‘Nationality or Domicile? The Present State of Affairs’ (1969) 128 Rec. des Cours 344–503).
IV. Modern trends
Since the middle of the 20th century, the use of nationality as a connecting factor has been declining internationally. While personal status is still often determined by referring to nationality in national conflicts codifications (see V.1.), it is no longer the sole connecting factor. In international family law, this is because a connection with regard to family relations using nationality will fail if the family members have different nationalities. Using the nationality of the male alone (ie in his role as the husband or father) would be a clear breach of the equality principle. After some hesitation, this was confirmed by courts in the 1990s at the latest (see for Germany: Federal Constitutional Court of Germany (BVerfG), 4 May 1971, 31 BVerfGE 58; 22 February 1983, 63 BVerfGE 181; 8 January 1985, 68 BVerfGE 384; for Italy: Corte di Cassazione, 26 February 1987 n 71,  Foro italiano I 2317; 25 November 1987 n 477,  Foro italiano I 1455) (→Constitutional law and private international law).
In those European legal systems that turned to the nationality principle in the 19th century, the integration of immigrants who arrive in the country due to work migration or as refugees is becoming the policy goal of law more and more often. Using habitual residence as a connecting factor is seen as a means of achieving this goal. It leads to the equal treatment of the entire resident population; in addition, it makes the courts’ work easier since it leads to a more frequent application of the municipal laws of the forum. This idea of integration – and because of the participation of the →United Kingdom, →Ireland, →Malta and Cyprus in legislation – EU conflict of laws relies on nationality only exceptionally (see V.3.). It has not played a significant role in treaties created by the →Hague Conference on Private International Law since 1957 (see V.2.).
There is a tendency in recent decades to give citizens a choice in matters of personal status between the laws determined by reference to nationality on the one hand, and the laws determined by reference to habitual residence (or domicile) on the other (→Domicile, habitual residence and establishment). This accords adequate weight to the ever more important right of self-determination. The citizen himself solves the dilemma of determining the applicable personal status law. This solution was recommended by the Institut de Droit international several times (resolution of 25 August 2005 on ‘Différences culturelles et ordre public en droit international privé de la famille’ ((2005) 71:2 Annuaire de l’Institut de Droit international 291, 292,  IPRax 559, 560, Rapporteur: Paul Lagarde); resolution of September 1989 on ‘La dualité des principes de nationalité et de domicile en droit international privé’ ((1987) 62:2 p. 1297Annuaire de l’Institut de Droit international 127,  IPRax 65, 66, Rapporteur: Yvon Loussouarn); for more details see Christian Kohler, ‘L’autonomie de la volonté en droit international privé: un principe universel entre libéralisme et étatisme’ (2013) 359 Rec. des Cours 285, 416 ff). Such a right to choose (→Party autonomy) is provided for in particular by the Italian Private International Law Act (Riforma del Sistema italiano di diritto internazionale private, Act No 218 of 31 May 1995 in Gazz.Uff., Supplemento Ordinario No 128 of 3 June l995, as amended, henceforth Italian PILA) in art 46(1), (2) and art 21, 22 Succession Regulation (Regulation (EU) No 650/2012 of the European Parliament and of the Council of 4 July 2012 on jurisdiction, applicable law, recognition and enforcement of decisions and acceptance and enforcement of authentic instruments in matters of succession and on the creation of a European Certificate of Succession,  OJ L 201/107; →Rome IV Regulation). In the Italian PILA, as a rule, nationality is used as the connecting factor. Connection by means of residence can only exceptionally be achieved by →choice of law. This rule-exception relationship is reversed in the Succession Regulation. A similar trend is starting to become apparent in matrimonial property law. According to art 15(1), referring to art 14(1) no 1 EGBGB, the matrimonial property regime is constituted by the shared home laws of the spouses. However, they can make a choice of law, thus rendering the laws at the place of residence of one of the spouses applicable (art 15(2) no 2 EGBGB). In a similar vein, spouses who do not share a common nationality can elect the law governing general effects of marriage under art 9(3) of the Spanish Civil Code (Código Civil of 24 July 1889, Geceta de Madrid No 206, 25 July 1889; henceforth Spanish CC). Articles 16 lit a), 17(1) lit a) Commission Proposals for the Matrimonial Property Regulations (Proposal for a Council Regulation on jurisdiction, applicable law and the recognition and enforcement of decisions in matters of matrimonial property regimes (COM(2011) 126/2)) reverse this rule-exception relationship. The matrimonial property regime is the law of the state of the spouses’ habitual common residence; however, the spouses can elect the law of the state of their first common habitual residence after they got married. According to art 10(2), (3), 17b(2) EGBGB, spouses, registered partners or parents can decide whether their name or their child’s name should be governed by the laws of nationality or of residence. The possible examples are legion.
4. New rule-exception relationship
Use of nationality is becoming a subsidiary or alternative →connecting factor besides the habitual residence rather than the main principle – or so seems to be the trend in Europe. For instance, art 17(1) lit a), b) of the aforementioned Commission Proposals for the Matrimonial Property Regulations provides that, when no choice of law is possible, the law of the common residence governs questions of →matrimonial property. Only in the absence of this connection is nationality relied upon to determine the applicable law. The same hierarchy is applied by art 8 Rome III Regulation. The so-called ‘Kegel’s ladder’ (→Kegel, Gerhard) is thus turned upside-down (cf art 14(1) nos 1, 2 EGBGB).
V. Current regulation
A number of legal systems use nationality as either the sole connecting factor or as one of several connecting factors. As of yet, the nationality principle has neither declined in nor disappeared from national codifications; rather, it has merely decreased in relative importance. This is because in more recent European codifications, residence has partially replaced nationality as a connecting factor. In Europe, the following examples can be given of countries which use nationality as a connecting factor when determining personal status laws (this information was taken from the country reports in Rainer Hausmann ‘Anhang zu Art 4 EGBGB, Länderberichte’ in Dieter Henrich and others (eds), Julius von Staudingers Kommentar zum Bürgerlichen Gesetzbuch: Einführungsgesetz zum Bürgerlichen Gesetzbuche/IPR Art 3–6 (Internationales Privatrecht – Allgemeiner Teil) (Sellier – de Gruyter 2013)): →Albania, →Belgium, →Bosnia and Herzegovina, →Bulgaria, →Germany, →France, →Greece, →Italy, →Liechtenstein, →Luxembourg, →Macedonia, FYR, →Montenegro, the →Netherlands, →Poland, →Portugal, →Romania, →Serbia, →Slovakia, →Slovenia, →Spain, →Turkey and →Hungary, as well as the →Russian Federation and the other successor states of the Soviet Union (ie Armenia, p. 1298→Belarus, →Georgia, →Kazakhstan, Kyrgyzstan, Moldova, Tajikistan, Turkmenistan, →Ukraine and Uzbekistan). The lex patriae was also applicable in →Lithuania, although only for a limited time (from 1994 to 2001). In Asia, the following countries use the nationality principle; particular examples include: →Japan, the Republic of →China (→Taiwan), the Republic of →Korea (South Korea), and →Thailand. In Latin America, some countries follow the nationality principle (eg Cuba) and some apply it unilaterally to their nationals (→Chile, →Ecuador, →Colombia); there are also some which have rejected it in favour of the domicile principle (eg →Brazil in 1999, →Venezuela etc) or which have always followed the domicile principle (eg →Paraguay, →Peru, →Uruguay etc). Most conflict of laws systems in the North African and Arabic region follow the nationality principle (eg →Egypt, Algeria, Iraq, →Iran, Jordan, Libya, Morocco, Somalia, Sudan, Syria, →Tunisia etc), as do →Angola, Gabon, →Mozambique, Senegal and Togo.
A number of older treaties dealing with personal status matters use nationality as a connecting factor. However, nationality ceased to play a significant role as of the mid-20th century; this is revealed by an analysis of the treaties of the Hague Conference on Private International Law (see Jürgen Basedow, ‘The Law of Open Societies: Private Ordering and Public Regulation of International Relations. General Course on Private International Law’ (2013) 360 Rec. des Cours 249). The Latin American Código de Derecho Internacional Privado of 20 February 1928 (Código Bustamante, Bustamante Code on Private International Law of 20 February 1928, OAS, Law and Treaty Series, no 34) left it to the treaty states to decide whether personal status laws were to be determined by referring to domicile or to nationality (→Domicile, habitual residence and establishment).
According to art 20 TFEU, citizenship of a Member State confers Citizenship of the Union. However, this is not a conflict-of-laws connecting factor. In European conflict of laws, the law pertaining to →personal status matters is generally determined by reference to habitual residence. Even though the EU regulations are uniform law and thus govern all situations, not just those with a connection to the Internal Market, the idea of integration leads to the replacement of the nationality principle. Nevertheless, through a special choice of law, one may usually elect the law of one’s home state (Succession Regulation; Commission Proposals for the Matrimonial Property Regulations, see IV.2.; art 5(3) lit c) Rome III Regulation; art 15 Maintenance Regulation with art 8(1) lit c) Hague Maintenance Protocol 2007 (Hague Protocol of 23 November 2007 on the law applicable to maintenance obligations,  OJ L 331/19)). According to art 8 lit c) Rome III Regulation, in the absence of a choice of law, the third subsidiary connection is that the law governing divorce will be determined by referring to the law of the state of which both spouses are nationals at the time the court is seized. According to art 7(3) lit c) Rome I Regulation (Regulation (EC) No 593/2008 of the European Parliament and of the Council of 17 June 2008 on the law applicable to contractual obligations (Rome I),  OJ L 177/6; →Rome Convention and Rome I Regulation (contractual obligations)), in the case of life assurance, the law of the Member State of which the policyholder is a national can be elected as the law governing the contract.
Article 18 TFEU prohibits any discrimination based on nationality. With regard to conflict of laws, this only means that the unilateral use of nationality as a connecting factor is not allowed within the TFEU’s sphere of application. Multilateral conflict rules using nationality as a connecting factor are not discriminatory (see Jürgen Basedow, ‘Das Staatsangehörigkeitsprinzip in der Europäischen Union’  IPRax 109; Heinz-Peter Mansel, ‘The Impact of the European Union’s Prohibition of Discrimination and the Right of Free Movement of Persons on the Private International Law Rules of Member States’ in Katharina Boele-Woelki and others (eds), Convergence and Divergence in Private International Law: Liber Amicorum Kurt Siehr (Eleven International Publishing 2010) 289, 296 ff). The Union itself uses this connecting factor in its capacity as legislator in art 8 lit c) Rome III Regulation. Furthermore, using the nationality of the person concerned can regularly be justified (see Heinz-Peter Mansel, ‘The Impact of the European Union’s Prohibition of Discrimination and the Right of Free Movement p. 1299of Persons on the Private International Law Rules of Member States’ in Katharina Boele-Woelki and others (eds), Convergence and Divergence in Private International Law: Liber Amicorum Kurt Siehr (Eleven International Publishing 2010) 289, 297 f). For people holding multiple citizenships, see VI.3.
VI. Particular problems in practice
1. Failure in individual cases
Using nationality as a connecting factor may lead to a system of laws to which the person concerned has no connection and which appears culturally foreign to him; the same problem might occur when using habitual residence: ‘As determinants of the personal law, nationality yields a predictable but frequently an inappropriate law; domicile yields an appropriate but frequently an unpredictable law’ (James Fawcett, Janeen Carruthers and Peter North, Cheshire, North & Fawcett’s Private International Law (14th edn, OUP 2008) ch 9, 7(a)(ii)). Suggestions have been made to use ordinary residence rather than nationality as the connecting factor if the person concerned obviously and clearly only has ties to the country that has been his country of residence for a period of years (on this see Heinz-Peter Mansel, Personalstatut, Staatsangehörigkeit und Effektivität (CH Beck 1988) 466 ff with further references). This suggestion has not been well-received due to the legal uncertainty created by having to make case-by-case decisions. General →escape clauses, such as the one found in art 8 Book 10 Dutch New Civil Code (Nieuw Burgerlijk Wetboek of 1 January 1992, henceforth Dutch CC) or art 19 of the Belgian Code of Private International Law (Code de Droit International Privé, Loi du 16 juillet 2004 portant le Code de droit international privé, MB 27 July 2004, 57344, as amended, henceforth Belgian PILA), are rarely used to this end.
2. Composite legal systems
Nationality itself is not a sufficiently clear connecting factor in cases of states with composite legal systems (eg →Canada, →Iran, Iraq, →Israel, →Spain, the →United Kingdom, the →USA etc). An additional connection needs to be made at a lower level. However, this is not a specific problem of use of nationality as the connecting factor. Individual national conflicts laws, treaties and EU regulations contain provisions for such lower level connections. Examples include: art 14 Rome III Regulation, art 36 Succession Regulation, art 16 Hague Maintenance Protocol 2007 (interlocal conflict of laws), art 15 Rome III Regulation, art 37 Succession Regulation, art 16 Hague Maintenance Protocol 2007 (interpersonal conflict of laws).
3. Multiple nationalities
The number of people holding multiple nationalities is constantly rising due to the fact that it is more and more common nowadays for both parents to be able to confer their citizenship (see I.3.a)). If a person has more than one nationality, a decision has to be made as to which one is decisive. Most national laws contain provisions for such cases and either (i) favour the laws of the home state in which the person is ordinarily resident or, subsidiarily, the home state to which the person actually has the closest ties (eg art 19 Chinese Statute of Application of Law to Foreign Civil Relations (adopted at the 17th session of the Standing Committee of the 11th National People’s Congress on 28 October 2010, effective 1 April 2011, henceforth Chinese PILA); art 11(1) Book 10 of the Dutch CC, etc), or (ii) only use actual ties (eg art 5(1) German EGBGB; art 2(1) Polish Private International Law Act (Official Journal 2011 No 80, pos 432, henceforth Polish PILA), etc).
If a person holds the nationality of the forum state, most laws only use this nationality (eg art 9(1) Austrian Federal Code on Private International Law (Bundesgesetz über das internationale Privatrecht of 15 June 1978, BGBl. No 304/1978, as amended, henceforth Austrian PILA); art 3, § 2 no 1 Belgian PILA; art 5(1) German EGBGB; art 19(2) Italian PILA; art 2(1) Polish PILA; art 27 Portuguese Código civil (Direitos dos estrangeiros e conflitos de leis); art 9, § 9 Spanish CC etc). Non-codification of the preference of the forum’s nationality is rare (examples include art 1262(1) Armenian Civil Code (Civil code of Armenia as adopted in 1998, Division 12, art 1253–93); art 19 Chinese PILA; art 11(1) Book 10 of the Dutch CC). Under the former, unwritten German conflict laws, the effective nationality – meaning the nationality of the state to which the person has the closest connection – was also determinative in cases of people holding German nationality and at least one other nationality (see German Federal Court of Justice (BGH), 20 June 1979,  NJW 2468). Conflicts rules that p. 1300allow a choice between home laws often permit the person holding multiple nationalities to choose any of their home laws (see art 22 Succession Regulation). The same applies in cases where nationality establishes the jurisdiction of one of the home states’ courts. The ECJ made a similar decision with regards to jurisdiction for recognition in Hadadi v Hadadi (C-168/08,  ECR I-6871). If the applicable law is to be determined through nationality and there is a contest between the nationalities of different Member States, according preference to the forum’s nationality might be a breach of art 18 TFEU (in this sense Jürgen Basedow, ‘Das Staatsangehörigkeitsprinzip in der Europäischen Union’  IPRax 109, 114; Heinz-Peter Mansel, ‘The Impact of the European Union’s Prohibition of Discrimination and the Right of Free Movement of Persons on the Private International Law Rules of Member States’ in Katharina Boele-Woelki and others (eds), Convergence and Divergence in Private International Law: Liber Amicorum Kurt Siehr (Eleven International Publishing 2010) 291, 298 with further references). The German Federal Court of Justice did not have to take a position on this question and could leave it unanswered (German Federal Court of Justice (BGH), 19 February 2014  NJW 1381, 1384). The ECJ did not have to take an explicit position either. However, it has implicitly indicated that preference for the forum state might be discriminatory in certain circumstances. In Garcia Avello (Case C-148/02 Carlos Garcia Avello v Belgian State  ECR I-11613) the Court held that, with regard to a Spanish-Belgian national who ordinarily resided in Belgium, the application of Belgian name laws would be discriminatory if the parents wanted to give the child a name according to the laws and traditions of Spain. In effect, the CJEU held that the preference for the forum state’s nationality or effective nationality was discriminatory; the Court allowed a choice of law between the two home laws. Where there is no choice of law, or where there are multiple people involved and they do not all make the same choice, a decision has to be made on a case-by-case basis. The Garcia Avello decision at least shows that a mechanical application of a preference rule violates art 18 TFEU (Jürgen Basedow, ‘Das Staatsangehörigkeitsprinzip in der Europäischen Union’  IPRax 109, 114).
4. Stateless people, refugees and asylum-seekers
The personal status of stateless people and refugees is primarily governed by treaties. In most cases, residence is used to determine the personal status. Of particular importance for stateless people is the United Nations Conventions relating the Status of Stateless Persons of 28 September 1954 (360 UNTS 117); for refugees, the most important treaty is the Geneva Convention of 22 April 1951 relating to the Status of Refugees (189 UNTS 137).
The treaty rules are reflected in national legislation. For people who are stateless, most national laws apply either (i) the laws of the place of habitual residence and, occasionally, subsidiarily, the laws of the place of simple residence (eg art 9(1) Austrian PILA; art 3, § 3 (refugees) § 4 (stateless) Belgian PILA; art 5(2) EGBGB etc) or (ii) the laws of the place of registered residence and, subsidiarily, the laws of the place of simple residence (eg art 1262(2) Armenian Civil Code; art 19(1) Italian PILA; art 3 Polish PILA etc). Occasionally, the same laws are applied in cases where the nationality of a person cannot be determined (eg art 3, § 4 Belgian PILA; art 5(2) EGBGB; art 3 Polish PILA).
Asylum-seekers and those who have already received asylum are treated as refugees within the meaning of the Refugee Convention under some national laws even though they do not meet the criteria of the convention (eg § 2(2) Asylum Procedure Act (Asylverfahrensgesetz (AsylVfG) of 2 September 2008, BGBl. I 1798, as amended)). In other countries, however, for such individuals, the laws of the asylum state are applied to personal status matters (art 1262(3) Armenian Civil Code).
5. Changes of home state in public international law
If a new government is exercising sovereignty in a person’s home state – either because of an annexation, occupation, putsch, revolution or a collapse of the old government – and the forum state does not recognize this change, it is uncertain if a new nationality introduced by the new government has any effect in conflict of laws. It is mostly accepted in cases in which the new government effectively exercises a law-controlling power in the territory (see Joe Verhoeven, ‘Relations internationales de droit privé en l’absence de reconnaissance d’un Etat, p. 1301d’un gouvernement ou d’une situation’ (1985-II) 192 Rec. des Cours 9, 158 ff and 179 ff).
A lot of states provide for a so-called ‘home jurisdiction’ in matters of personal law, family law and the laws of succession. The courts of these states have international jurisdiction for any lawsuit or motion brought by their nationals. In particular, a person can have matters relating to personal status (eg divorce (→Divorce and personal separation), descent, →adoption etc) resolved with immediate binding effect for his home state and its administrative agencies. Article 14, 15 French CC and the legal systems that have adopted this rule provide for an even more comprehensive home jurisdiction. According to this rule, a French national can sue a foreigner in a French court. At the same time, a foreigner can sue a French national in a French court. The wording of this rule is limited to contractual matters, but French courts have extended it to all types of legal disputes.
Home jurisdiction rules extend the duty of other parties to appear in front of a court. Thus, the jurisdiction under art 14, 15 French CC is deemed to be exorbitant under art 3(1) Brussels I Regulation (art 5(2) and art 76(1) lit a) Brussels I Regulation (recast)). That notwithstanding, a claimant residing in France can rely on it with regard to a defendant residing outside the EU, according to art 4(2) Brussels I Regulation (art 6(2) Brussels I Regulation (recast)). Due to their potentially discriminatory effect, home jurisdiction rules are rarely used in EU legislation; a limited example can be found in the Brussels IIa Regulation (see for an example I.2.), art 6 Maintenance Regulation (common nationality as a means of determining subsidiary jurisdiction), and art 10 Succession Regulation (subsidiary jurisdiction of the home state when the habitual residence of the deceased at the time of death is not located in a Member State).
Louis d’Avout, ‘La lex personalis entre nationalité, domicile et résidence habituelle’ in Mélanges en l’honneur du Professeur Bernard Audit (L.G.D.J. 2014) 17;
Jürgen Basedow, ‘Das Staatsangehörigkeitsprinzip in der Europäischen Union’  IPRax 109;
Oliver Dörr, ‘Nationality’ in Rüdiger Wolfrum (ed), Max Planck Encyclopedia of Public International Law (OUP 2012);
Hélène Gaudemet-Tallon, ‘Nationalité, statut personnel et droit de l´homme’ in Heinz-Peter Mansel and others (eds), Festschrift für Erik Jayme (Sellier European Law Publishers 2004) 205 ff;
Jürgen Habermas, ‘Citizenship and National Identity’ in Bart Van Steenbergen (ed), The Condition of Citizenship (Sage 1994) 20ff;
Erik Jayme, ‘Identité culturelle et intégration: le droit international privé postmoderne’ (1995) 251 Rec. des Cours 9;
Christian Kohler, ‘L’autonomie de la volonté en droit international privé: un principe universel entre libéralisme et étatisme’ (2013) 359 Rec. des Cours 285;
Alexander Lüderitz, ‘Anknüpfung im Parteiinteresse’ in Alexander Lüderitz and Jochen Schröder (eds), Internationales Privatrecht und Rechtsvergleichung im Ausgang des 20. Jahrhunderts. Bewahrung oder Wende? Festschrift für Gerhard Kegel (Metzner 1977) 31;
Pasquale Stanislao Mancini, ‘Della nazionalità come fondamento del dritto delle genti: prelezione al corso di dritto internazionale e marittimo pronunziata nella R. Università di Torino nel dì 22 gennaio 1851’ published by Erik Jayme (G Giappichelli 1994; first published by Botta 1851; later in Diritto internazionale, Marghieri 1873) 19;
Heinz-Peter Mansel, Personalstatut, Staatsangehörigkeit und Effektivität (CH Beck 1988);
Heinz-Peter Mansel, ‘Die kulturelle Identität im internationalen Privatrecht’ in Georg Nolte and others (eds), Pluralistische Gesellschaften und Internationales Recht (CF Müller 2008) 137;
Heinz-Peter Mansel, ‘The Impact of the European Union’s Prohibition of Discrimination and the Right of Free Movement of Persons on the Private International Law Rules of Member States’ in Katharina Boele-Woelki and others (eds), Convergence and Divergence in Private International Law: Liber Amicorum Kurt Siehr (Eleven International Publishing 2010) 291;
Yuko Nishitani, ‘Gobal Citizens and Family Relations’  ELR 134;
Joe Verhoeven, ‘Relations internationales de droit privé en l’absence de reconnaissance d’un Etat, d’un gouvernement ou d’une situation’ (1985-II) 192 Rec des Cours 9;
Olivier Vonk, Nationality Law in the Western Hemisphere (Brill/Nijhoff 2014);
Louis I de Winter, ‘Nationality or Domicile? The Present State of Affairs’ (1969-III) 128 Rec. des Cours 344.