Abū Muḥammad ʿAbd Allāh ibn Yūsuf ibn al-Ḥāfiẓ (Arabic: أبو محمد عبد الله بن يوسف بن الحافظ; 1151–1171), better known by his regnal name al-ʿĀḍid li-Dīn Allāh (Arabic: العاضد لدين الله, lit. 'Strengthener of God's Faith'), was the fourteenth and last caliph of the Fatimid dynasty, and the twenty-fourth imam of the Hafizi Isma'ili branch of Shi'a Islam, reigning from 1160 to 1171.
Like his two immediate predecessors, al-Adid came to the throne as a child, and spent his reign as a puppet of various strongmen who occupied the vizierate. He was a mostly helpless bystander to the slow collapse of the Fatimid Caliphate. Tala'i ibn Ruzzik, the vizier who had raised al-Adid to the throne, fell victim to a palace plot in 1161, and was replaced by his son, Ruzzik ibn Tala'i. Ruzzik was in turn overthrown by Shawar in 1163, but the latter lasted only a few months in office before being overthrown by Dirgham. The constant power struggles in Cairo enfeebled the Fatimid state, allowing both the Crusader Kingdom of Jerusalem and the Sunni ruler of Syria, Nur al-Din, to advance their own designs on the country. The Crusaders repeatedly invaded Egypt, extracting tribute and ultimately aiming to conquer it; in turn, Nur al-Din supported Shawar's bid to retake the vizierate from Dirgham, and sent his general Shirkuh to counter the Crusaders. For a while, Shawar played the Crusaders and Syrians against one another, but in January 1169, Shirkuh overthrew Shawar, occupied Cairo and became vizier. When Shirkuh died shortly after, he was succeeded by his nephew, Saladin.
