Abu Yusuf Yaqub al-Mansur

Abu Yusuf Ya'qub al-Mansur (ابو يوسف يعقوب المنصور 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.

Dynastic and Iberian Wars
Al-Mansur's father was killed in Portugal on July 29, 1184; upon reaching Seville with his father's body on August 10, he was immediately proclaimed the new caliph. Al-Mansur vowed revenge for his father's death, but fighting with the Almoravids, who had been ousted from the throne, delayed him in Africa. After inflicting a new defeat on the Almoravids, he set off for the Iberian Peninsula to avenge his father's death.

His 13 July 1190 siege of Tomar, center of the Portuguese Templars failed to capture the fortress. However, further south he in 1191 recaptured a major fortress, Paderne Castle and the surrounding territory near Albufeira, in the Algarve - which had been controlled by the Portuguese army of King Sancho I since 1182. Having inflicted other defeats on the Christians and captured major cities, he returned to Morocco with three thousand Christian captives.

Upon Al-Mansur's return to Africa, however, Christians in Iberian Peninsula resumed the offensive, capturing many of the Moorish cities, including Silves, Vera, and Beja.

When Al-Mansur heard this news, he returned to the Iberian Peninsula, and defeated the Christians again. This time, many were taken in chained groups of fifty each, and later sold in Africa as slaves.

While Al-Mansur was away in Africa, the Christians mounted the largest army of that period, of over 300,000 men, to defeat Al-Mansur. However, immediately upon hearing this, Al-Mansur returned again to Iberia and defeated Castilian King Alfonso VIII Alfonso's army in the Battle of Alarcos, on July 18, 1195. It was said that Al-Mansur's forces killed 150,000 and took money, valuables and other goods "beyond calculation". It was after this victory that he took the title al-Mansur Billah ("Made Victorious by God").

Internal policy
During his reign, Al-Mansur undertook several major projects. He built the Koutoubia and El Mansouria mosques in Marrakech and the kasbah of the Udayas, accessed by Bab Agnaou and Bab Ksiba in the southern part of its medina. He attempted to build what would have been the world's largest mosque in Rabat. However, construction on the mosque stopped after al-Mansur died. Only the beginnings of the mosque had been completed, including the Hassan Tower.

Al-Mansur protected the philosopher Averroes and kept him as a favorite at court. Like many of the Almohad caliphs, Al-Mansur was religiously learned. He favored the Zahirite or literalist school of Muslim jurisprudence per Almohad doctrine and possessed a relatively extensive education in the Muslim prophetic tradition; he even wrote his own book on the recorded statements and actions of the prophet Muhammad. Mansur's Zahirism was clear when he ordered his judges to exercise judgment only according to the Qur'an, said recorded statements and absolute consensus. Mansur's father Abu Yaqub appointed Cordoban polymath Ibn Maḍāʾ as chief judge, and the two of them oversaw the banning of all non-Zahirite religious books during the Almohad reforms; Mansur was not satisfied, and when he inherited the throne he ordered Ibn Maḍāʾ to actually undertake the burning of such books.

Death and heritage
He died in Marrakech, Morocco.

His victory in Alarcos was remembered for centuries later, when the tide of war turned against the Muslim side. It is recounted by the historian Abou Mohammed Salah ben Abd el-Halim of Granada in his 1326 "Roudh el-Kartas" ("History of the Rulers of Morocco").

The town of Moulay Yacoub, outside of Fez, Morocco, is named after Al-Mansur, and is best known for its therapeutic hot springs.