Tanzimat has been classically treated as a break with the tradition (ancien régime) and opening into the modern. Historians have debated the direction of the rupture and documented the reinvention of the state. However, the modernism of the classical historiography on Tanzimat (Berkes, Kuran, Lewis) has exclusively focused on the birth of modern institutions and ideas at the heart of the empire. In this paper, I would like to undo this hegemonic interpretation by focusing on the place of the oath in the Ottoman statecraft and its transformation following the Greek Independence. Ottoman and modern historians emphasized the abolition of the Janissary as the cardinal event while minimizing the Greek affair. Following Philliou (2011), I would like to rethink Tanzimat in view of the ‘Greek Interregnum’ (Rûm Fetreti) and the ruination of the sovereign-subject bond. Oath, I argue, was the immemorial governmental technology binding the subjects of the empire (teba’a) to the Sultan. With Tanzimat, as Abu-Manneh (2001) noted, the asymmetry of the oath is ‘reversed’: Sultan emerges as a voice and swears by his own name in order to suture the continuum between the people and the sovereign. After briefly addressing the authority of the oath in the classical age, I will show how in the emergent age of nationalism it failed to produce subjection. I will trace this failure through documents from the Ottoman archives and Greek revolutionary writings.