Abu Yusuf Ya'qub al-Mansur ( Abū Yūsuf Ya‘qūb al-Manṣūr) (c. 1160 Morocco – January 23, 1199 Marrakech, Morocco), also known as Moulay Yacoub, was the third Almohad Caliph. Succeeding his father, al-Mansur reigned from 1184 to 1199. His reign was distinguished by the flourishing of trade, architecture, philosophy and the sciences, as well as by victorious military campaigns in which he was able to temporarily stem the tide of Christian Reconquista in the Iberian Peninsula.