of another Almoravid campaign at the tail end of 1100, led by Yusef's trusted lieutenant Mazdali ibn Tilankan. After a seven-month siege, Alfonso and Jimena, despairing of the prospects of staving off the Almoravids, set fire to the great mosque in anger and abandoned the city. Yusef had finally conquered Valencia achieving dominance over eastern al-Andalus. He receives mention in the oldest Spanish epic Poema del Cid, also known as El Cantar del Mio Cid. Description and character "A wise and shrewd man, neither too prompt in his determinations, nor too slow in carrying them into effect", Yusef was very much adapted to the rugged terrain of the Sahara and had no interests in the pomp of the Andalusian courts. Unlike many other Muslim leaders of the time, Yusef spoke Arabic poorly. According to medieval Arabic writers, Yusuf was of average build and stature. He is further described as having "had a clear brown complexion and he had a thin beard. His voice was soft, his speech elegant. His eyes were black, his nose was hooked, and he had fat on the fleshy portions of his ears. His hair was curly and his eyebrows met above his nose." Legacy His son and successor, Ali ibn Yusuf, was viewed as just as devout a Muslim as his father. Córdoba, in about 1119, served as the launch pad for Andalusian insurrection. Christians on the northern frontier gained momentum shortly after his father's death, and the Almohads, beginning about 1120, were to engulf the southern frontier. This ultimately led to the disintegration of Yusef's hard-gained territories by the time of Ibrahim ibn Tashfin (1146) and Ishaq ibn Ali (1146–1147), the last of the Almoravid dynasty. Ali ibn Yusef in 1135 exercised good stewardship by attending to the University of Al-Karaouine and ordering the extension of the mosque from 18 to 21 aisles, expanding the structure to more than 3,000 square meters. Some accounts suggest that to carry out this work Ali ibn Yusef hired two Andalusian architects, who also built the central aisle of the Great Mosque of Tlemcen, Algeria, in 1136. In popular culture In the 1961 movie El Cid, Yusuf ibn Tashfin is portrayed, under the name "Ben Yussuf", by Herbert Lom. Yusuf appears in Age of Empires II: The Conquerors as one of the primary antagonists in the "El Cid" campaign. However, he is described as "never showing his face",