|Biographical detail : ||The Caliph Marwan II, a descendent of Uqbah the founder of Qayrawan, appointed him the governor of Cordoba in 746.
Among 732 and 755, twenty-three governors succeeded one another in Spain, Yusuf was one such governor. In 755 he learnt that an Ummayad ruler by the name of Abdul Rahman had landed in the South of Granada. The battle on the banks of the Guadalquivir in 756 decided the issue. Abdur Rahman captured Cordoba and Yusuf sought safety in flight and was finally slain near Toledo.
In 777 his son-in-law invited Charlemagne to fight against Abdul Rahman but the Frankish army was defeated, one of the leaders who fell was Ronald who had been immortalised in French literature.