European criminal law (ECL) and international criminal law (ICL) are usually put together because of what they are not, ie, state law. To that extent, both branches successfully challenge – together with other past and current instances of non-state penal jurisdictions, such as the Native American tribes in the USA – the putative monopoly of the state over jurisdiction in criminal matters. However, as the EU and the international community are ‘peripheral’ jurisdictions created by the states, and despite the autonomy and autarchy inherent to the very concept of jurisdiction, the latter remain deeply implicated in the way ECL and ICL are produced and applied, generating a paradoxical and potentially conflictual relationship. Such implication reflects on the subsidiarity/primacy of those legal branches vis-à-vis state powers, as well as on their own structure and contents. ECL and ICL share similar features in the field of judicial cooperation, implementing ‘vertical’ models based on the recognition of the active party’s interests, to the detriment of traditional ‘horizontal’ models.