Las Navas de Tolosa and the changing balance of power.

The battle of Las Navas de Tolosa was a product of the longue durée: a military and political event that marked merely one particular point in a long social and cultural evolution in the Iberian peninsula that had been initiated by the Arab–Berber invasion of 711 and redirected by a resurgence of the Christian population, both in the northern realms of the peninsula and in al-Andalus, where the continuing presence of the muwāllads came to be a critical factor. That resurgence, made possible by the limited cohesion of Andalusi civil society and the associated fragility of the Umayyad regime, was profoundly conditioned by social and cultural accommodation to Christian northwestern Europe. [ABSTRACT FROM AUTHOR]