Centering the career of Cameroonian diplomat Paul Bamela Engo during the negotiation of the UN Convention on the Law of the Sea, this article makes a methodological intervention in the historiography of multilateral treaty-making. It reads through and against the grain of dominant narratives of oceanic constitution-making, and offers counter-narratives that serve as conceptual and mobilizational resources in contemporary struggles. It examines how the ‘stock story’ of the emergence of the resource regime for seabed minerals as the common heritage of mankind erases the radical alternatives that were proposed by Third World actors and their efforts to write them into law and sorts these actors into trope-laden categories of ‘extremist’ and ‘m...