'Abd al-Mu'min ibn 'Ali

(born 1094, Tagra, kingdom of the Hammadids—died 1163, Rabat, Almohad empire) Berber caliph (1130–63) of the Almohad dynasty. Around 1117 he fell under the sway of Ibn Tumart, founder of the Almohad religious movement, and joined him in opposing to the ruling Almoravid dynasty. He succeeded Ibn Tumart on the latter's death in 1130 and for the next 17 years carried on the struggle against the Almoravids. After defeating them at Marrakech in 1147, he massacred many of the city's inhabitants, made Marrakech his home base, and conquered all of North Africa west of Egypt.