This article examines the reasons why Suleyman the Magnificent executed his son Sehzade Mustafa during the Nahgvan military campaign of 1553. According to the dominant narrative in both Ottoman sources and academic literature, Suleyman's concubine and later wife Harem Sultan and her closest ally, Suleyman's son-in-law Rustem Pasha, plotted against Mustafa in order to save the throne for one of Hurrem's own sons. Though the latter was widely beloved, this scheme cost him his father's favor. Afterward, however, the sultan regretted the decision and dismissed Rustem Pasha from his position as grand vizier. This article examines the roles of Sultan Suleyman, Sehzade Mustafa, Harem Sultan, and Rustem Pasha in the Ottoman, Venetian, Habsburg, French, and Persian sources, investigating why the sultan executed the prince in the context of the Ottoman succession experience. Adding complexity to the common narrative, this article concludes that the sultan, who was losing his authority to the prince, desired to consolidate his power and to remove his dynasty from the competition between social groups that had characterized earlier succession struggles.