In 933/1527, during the plague, imam al-Mutawakkil Yaḥyā Sharaf al-Dīn (d. 965/1557), the first Zaydi imam to rule over both Upper and Lower Yemen, composed a will (waṣīya). This document, recently discovered in an understudied biography of the Zaydi imam, opened up the possibility of dynastic transfer in the Zaydi imamate. Previously, the formation of dynasties in Zaydi Yemen has been associated with the Qasimid period of the seventeenth to nineteenth centuries and linked to the century of Ottoman rule in the region. This new evidence indicates that the development of the theory and practice of dynasticism predates the Ottoman conquest of Yemen and has local roots. This paper analyzes the will and situates it in the broader context of sixteenth-century political transformation in Yemen. By placing it within the history of Zaydi political thought and practice, it uncovers how the tension between the meritocratic principle underlying Zaydi political theory that prevented the formation of dynasties and the practical need to stabilize the transfer of power between rulers was resolved in the Sharaf al-Dīn period.