In their African holdings, the Almohads encouraged the establishment of Christians even in Fez, and after the Battle of Las Navas de Tolosa they occasionally entered into alliances with the kings of Castile. They were successful in expelling the garrisons placed in some of the coast towns by the Norman kings of Sicily. The history of their decline differs from that of the Almoravids, whom they had displaced. They were not assailed by a great religious movement, but lost territories, piecemeal, by the revolt of tribes and districts. Their most effective enemies were the Banu Marin (Marinids) who founded the next dynasty. The last representative of the line, Idris II, 'al-Wathiq', was reduced to the possession of Marrakesh, where he was murdered by a slave in 1269.