This article analyses the way in which international administrations exercising governmental power in post-conflict territories justify their political authority in the absence of democratic legitimacy. Looking at the administrations in Bosnia, Kosovo, and East Timor, the article focuses on their establishment, their mandates, and their government practices and identifies five different sources of authority: consent, delegation, the maintenance of peace and security, the promotion of human rights and democracy, and the provision of government. However, all of these sources are contested. In particular the practices of international administrations, their lack of accountability and their limited effectiveness in providing government, undermine their authority. The article concludes by highlighting some possible avenues for enhancing the authority of international administrations.