The Banu Qasi were a Muslim dynastic family that ruled the region of the Ebro Valley in Spain. Their position and holdings originated from 7th century Visigothic realm, and they ruled the Ebro Valley from the 8th century to the 10th century. Their chief seat was Tudela, and they held also e.g Huesca. The family descended from the Visigothic count Cassius, hence the name "Banu Qasi", or "Sons of Cassius". In the beginning of 8th century, when Muslims invaded the peninsula, they allied with the conquerors and soon converted to Islam. It was a patrilineal dynasty: that is, the father's position and power was inherited by his sons, particularly the eldest son (primogeniture). They were allies of the newly-established kingdom of Pamplona in 9th century and enemies of the Asturian kingdom. A Muslim is a believer in or follower of Islam. ... A dynasty is a family or extended family which retains political power across generations, or more generally, any organization which extends dominance in its field even as its particular members change. ... This article is about the Spanish river. ... (7th century — 8th century — 9th century — other centuries) Events The Iberian peninsula is taken by Arab and Berber Muslims, thus ending the Visigothic rule, and starting almost 8 centuries of Muslim presence there. ... ( 9th century - 10th century - 11th century - other centuries) As a means of recording the passage of time, the 10th century was that century which lasted from 901 to 1000. ... The Visigoths,were one of the two main branches of the Goths (of which the Ostrogothi were the other), were one of the loosely-termed Germanic tribes that brought chaos to the late Roman Empire. ... Patrilineality is a system in which one belongs to ones fathers lineage; it generally involves the inheritance of property, names or titles through the male line as well. ... Primogeniture is inheritance by the first-born of the entirety of a parents wealth, estate or office, or in the absence of children, by collateral relatives in order of seniority of the collateral line. ...