To what extent should the doctrine of the separation of powers evolve in light of recent shifts in constitutional design and practice? Constitutions now often include newer forms of rights – such as socioeconomic and environmental rights – and are written with an explicitly transformative purpose. They also often reflect include new independent bodies such as human rights commissions and electoral tribunals whose position and function within the traditional structure is novel. The practice of the separation of powers has also changed, as the executive has tended to gain power and deliberative bodies like legislatures have often been thrown into a state of crisis. The chapters in this edited volume grapple with these shifts and the ways in which the doctrine of the separation of powers might respond to them. It also asks whether the shifts that are taking place are mostly a product of the constitutional systems of the global south, or instead reflect changes that run across most liberal democratic constitutional systems around the world.