Al-Mu'izz li-Din Allah was the fourth caliph of the Fatimid Caliphate, ruling from 953 to 975 CE. He is known for consolidating the power of the Fatimids in North Africa and establishing Cairo as the capital of the caliphate. His reign marked a period of cultural and economic prosperity. Under Al-Mu'izz, the Fatimid Caliphate expanded its territory, including parts of Tunisia and Egypt. He was a patron of the arts and sciences, promoting the development of Islamic architecture and scholarship. His leadership helped to strengthen the influence of the Shi'a branch of Islam in the region.