الفتح الإسلامي للأندلس
From the time of the Umayyad conquest of Hispania and throughout the Reconquista, marriage between Spanish and Umayyad royals was not uncommon. Early marriages, such as that of Abd al-Aziz ibn Musa and Egilona at the turn of the 8th century, was thought to help establish the legitimacy of Muslim rule on the Iberian Peninsula. Later instances of intermarriage were often made to seal trade treaties between Christian kings and Muslim caliphs.