Al-Qahir Billah was an important figure in Islamic history, known as the sixth caliph of the Fatimid Caliphate. He ruled from 1021 to 1036 CE and was recognized for his efforts to consolidate power and expand the caliphate's influence in North Africa and the Mediterranean region. His reign was marked by military campaigns and administrative reforms that strengthened the central authority of the caliphate. During his rule, Al-Qahir Billah faced various challenges, including internal dissent and external threats. He is often remembered for his attempts to promote Ismaili Islam and for his patronage of arts and culture, which contributed to the flourishing of Cairo as a center of learning and commerce during the Fatimid period.