'Abd al-'Aziz b. Marwan (d. 86/705) reigned as the amir of Egypt and wali al-'ahd (heir apparent) to the Islamic caliphate for over 20 years. This book intends to revive this largely forgotten amir and demonstrate the critical role he played in the formation of the Marwanid dynasty. The founding thesis of this study is that 'Abd al-'Aziz was appointed the amir of Egypt and second heir apparent due to the legitimacy his maternal lineage brought the nascent dynasty.