The twentieth century has witnessed a proliferation of forms of international engagement in areas that were typically governed by states. The involvement of international actors in the administration of territory is one of them. The League of Nations assumed a significant role in territorial administration in the 1920s when undertaking functions of guarantee and administration under the Treaty of Versailles. This type of engagement gained new attention in the era of the United Nations (UN). Both the emergence of peacekeeping and the revitalisation of the collective security system after the end of the Cold War sparked a revival of experiments in international administration. Today, there is growing confidence that the UN can perform tasks of governance in post-conflict situations. The Handbook on United Nations Multidimensional Peacekeeping Operations includes international administration of territory as one of the functions of multidimensional peacekeeping. However, the format and practice of these engagements is still subject to considerable debate. The enthusiasm about robust UN governance missions that prevailed at the time of the establishment of UN Interim Administration in Kosovo (UNMIK) and the UN Transitional Administration in East Timor (UNTAET) at the end of the 1990s has been tempered by criticism of the UN's style of governance and calls for a move to “a light footprint” agenda, limiting the role of the UN to the provision of assistance to existing governing authorities and local actors.