Following their decisive defeat in the Battle of Las Navas de Tolosa in 1212 the Almohads began collapsing, and in 1235 the governor of modern-day Western Algeria, Yaghmurasen Ibn Zyan declared his independence and established the Kingdom of Tlemcen and the Zayyanid dynasty. Warring with the Almohad forces attempting to restore control over Algeria for 13 years, they defeated the Almohads in 1248 after killing their Caliph in a successful ambush near Oujda. The Zayyanid Kingdom of Tlemcen during the rule of Abu Malek