Research on the UN Trusteeship System offers important insights into continuities and change of the sovereign system of states and especially the role of Intergovernmental Organizations (IGOs) as sites for normative and material contestation between multiple actors. Like its predecessor, the League of Nations Mandate System, the UN Trusteeship System aimed at preserving and not dismantling empire. The Trusteeship Council was dissolved in 1994 once it had completed its function, but its ideational underpinnings remain relevant today as evidenced by more recent international interventions in Kosovo, Somalia, East Timor, Afghanistan and Libya. UN-mandated interventions at the turn of the 21st century in Somalia, East Timor and Kosovo all indicated that the UN Security Council continues to engage in experiments of revitalizing trusteeship models to create missions tasked with similar responsibilities as its historical predecessor. The Trusteeship System gained scholarly attention from various fields mainly by looking at internationalized constellations, external governance and transnational advocacy networks.