The concept of a right, and the idea of human rights, were familiar abstractions on the brink of the twentieth century. But the history of political mobilization since shows that human rights had a transformative capacity in that century that no prior age had demonstrated. Through the twentieth century, human rights became institutionalized internationally in laws, movements, and organizations that transcended state-based citizenship and governance – which irrevocably changed the politics around them. Rights continued to evolve as the imperial world order transitioned to a postcolonial world of sovereign states as a primary form of political organization. Through twenty-six essays from experts around the world demonstrating how this period is historically distinctive, volume five of The Cambridge History of Rights is a comprehensive and authoritative reference for the history of rights in the twentieth and twenty-first centuries.