Experts dominate all facets of global governance, from accounting practices and antitrust regulations to human rights law and environmental conservation. In this study, Ole Jacob Sending encourages a critical interrogation of the role and power of experts by unveiling the politics of the ongoing competition for authority in global governance. Drawing on insights from sociology, political science, and institutional theory, Sending challenges theories centered on particular actors’ authority, whether it is the authority of so-called epistemic communities, the moral authority of advocacy groups, or the rational-legal authority of international organizations. Using in-depth and historically oriented case studies of population and peacebuilding, he demonstrates that authority is not given nor located in any set of particular actors. Rather, continuous competition for recognition as an authority to determine what is to be governed, by whom, and for what purpose shapes global governance in fundamental ways. Advancing a field-based approach, Sending highlights the political stakes disguised by the technical language of professionals and thus opens a broader public debate over the key issues of our time.