Ibn Toumert (The Son of Happiness) was another radical religious reformer who emerged at the beginning of the 12th century to preach a unitarian (tawhid) doctrine. His followers became known as El Mowahhadidoun, or the Almohads. By the time the fiery Toumert died at Tin Mal in 1128, he had gathered numerous Berber tribes around his banner.
Abd el Moumin, Toumert’s able warrior chieftain, kept Toumert’s death a secret for two years, while he established his power base and then proclaimed himself Caliph and Amir el Mumineen (Commander of the Faithful). Moumin seized Marrakech and Fez, defeated the Almoravids and controlled all Morocco by 1148. He later moved into Spain and raged across North Africa, defeating the Hilali Arab hordes at Sétif. By the time he died, Moumin had forged an empire even larger than that of the Almoravids, extending eastwards as far as Tripoli. Most of Muslim Spain was reduced to vassaldom under his son Yacoub Youssef. His grandson, Youssef Yacoub, consolidated Almohad power and won the title El Mansour (the Victorious) when he crushed the Christians under King Alfonso VIII of Castile at the battle of Alarcos, on 18 July 1195.

At the height of their power between 1160 and 1210, the Almohads built a number of famous landmarks (see box), as well as the unfinished Tour Hassan in Rabat, the Giralda in Seville and the Koutoubia Mosque in Marrakech. But, like their predecessors the Almoravids,they sank, perhaps inevitably, into silken decadence. In their time Alicante boasted 800 looms for weaving silk cloth and minted fine gold coinage, and paper was manufactured in Ceuta and Fez.
Towards the end of the dynasty, in 1230, Sultan el Mamoun was reduced to accepting 12,000 Christian cavalrymen from King Ferdinand of Castile and Leon in order to retake Marrakech from local dissidents. As part of the bargain he allowed the construction of a Catholic church in the city. A Marrakech bishopric subsisted until the 14th century to serve foreign mercenaries.