Al-Nuwayri, a Mamluk historian, on the First Crusade-
“The beginning of their (Spain’s) appearing, expanding and penetrating into the Islamic lands was in 478. This came about in the following way. When the kings of the land of Spain became divided after the Umayyads and each area fell into the hand of one king and the soul of each one disdained to be led by the other and to enter into obedience to anyone else, they were like the Party Kings in Persian times…”
This fragmentation of Muslim Spain “led to the disturbance of conditions and the conquering of Islamic countries by enemies. The first place they conquered was the city of Toledo in al-Andalus as we have related under the year 478…”
Hillenbrand, Carole, The Crusades- Islamic Perspectives, Edinburgh University Press, Edinburgh, 1999, p.54.