The Almohads: from Ibn Tumart's revolt to the conquest of Marrakesh

Ibn Tumart, a Masmuda Berber of the Hargha tribe from the Sous, studied in Córdoba and in the East, where he absorbed Ash'ari theology; Almohad hagiographers later claimed that he had studied with al-Ghazali, a meeting modern historians cannot confirm. Returning to the Maghreb around 1117, he preached a rigorous doctrine of God's absolute unity (tawhid) and attacked the Maliki jurists favoured by the Almoravids, the sale of wine, music, the mixing of the sexes and the custom of veiled men and unveiled women brought by the Almoravids from the Sahara. Expelled from town after town, he gathered his first disciples near Béjaïa, Abd al-Mu'min among them, defied the Almoravid ruler Ali ibn Yusuf and his jurists in Marrakesh and fled to his native Sous. Towards the end of Ramadan in late 1121 his followers recognised him as the Mahdi, the divinely guided restorer of the faith — in effect a declaration of war on the Almoravid state.

In 1122 he moved into the High Atlas, and about 1124 he made Tinmel, a defensible valley on the road from Marrakesh to the Sous, his base and spiritual centre, organising the Masmuda tribes into a strictly ranked community with a council of ten companions and an assembly of fifty sheikhs; his lieutenant al-Bashir enforced discipline harshly, culminating in a bloody purge in the winter of 1129–1130. For years the Almohads fought a mountain war that cut the roads south of Marrakesh, but their first descent into the plain ended in disaster at al-Buhayra, before Marrakesh, in the spring of 1130, and Ibn Tumart died that August. His death was kept secret, and some three years later Abd al-Mu'min — a Zenata Berber from near Tlemcen and so an outsider among the Masmuda — was proclaimed caliph, 'successor' of the Mahdi.

From 1141 Abd al-Mu'min led a long campaign around the Atlas and into the Rif, won over the Zenata of the central Maghreb, took Tlemcen and Oran (1144–1145) — near Oran the Almoravid ruler Tashfin ibn Ali met his death in March 1145 — captured Fez after a nine-month siege and in 1147, after a siege of many months, took Marrakesh (some reference works date its fall to 1146). The last Almoravid ruler, Ishaq ibn Ali, was killed and the city purged; Abd al-Mu'min made it his capital and founded the Kutubiyya Mosque there. In the following years the Almohads crossed into al-Andalus, took Béjaïa from the Hammadids (1152), routed the Arab Banu Hilal and Banu Sulaym at Sétif (1153) and enlisted them in their armies, and by 1160 ruled the coast as far as Tripoli. Their rule at first drove many Jews and Christians to convert or flee, yet it also patronised philosophers such as Ibn Tufayl and Ibn Rushd; the empire lasted until the Marinids took Marrakesh in 1269.