Cassius was a count in the Visigothic nobility who converted to Islam and traveled to Damascus to personally swear allegiance to the Umayyad caliph al-Walid in 714.

An apt illustration of the ambivilent loyalties of this dynasty, Musa ibn Musa and the Navarrese king Íñigo Arista were maternal half-brothers; Musa also married Arista's daughter, and married a daughter and nieces to other Basque princes. At the height of his power in the late 850s Musa controlled a territory that included Zaragoza, Tudela, Huesca and Toledo. Viewed as equivalent to the emir of Cordoba and the king of Asturias, Musa was referred to as “The Third King of Spain”.