The Almohad movement in North Africa in the twelfth and thirteenth centuries

"How did the Almohads manage to unite all of North Africa and a large part of Spain into one empire? Why did they ultimately fail to hold their empire together? Professor Le Tourneau deals with these questions in this critique of the powerful Islamic religious movement, initiated by Ibn Tumart among the Berber tribesmen of North Africa, which culminated in the creation of the huge Almohad empire in the twelfth century." -- Book jacket.