kind. Advance to Narbonne Despite the defeat at Tours, the Umayyads remained in control of Narbonne and Septimania for another 27 years, though they could not expand further. The treaties reached earlier with the local population stood firm and were further consolidated in 734 when the governor of Narbonne, Yusuf ibn Abd al-Rahman al-Fihri, concluded agreements with several towns on common defense arrangements against the encroachments of Charles Martel, who had systematically brought the south to heel as he extended his domains. He conquered Umayyad fortresses and destroyed their garrisons at the Siege of Avignon and the Siege of Nîmes. The army attempting to relieve Narbonne met Charles in open battle at the Battle of the River Berre and was destroyed. However, Charles failed in his attempt to take Narbonne at the Siege of Narbonne in 737, when the city was jointly defended by its Muslim Arab and Berber, and its Christian Visigothic citizens. Carolingian dynasty Reluctant to tie down his army for a siege that could last years, and believing he could not afford the losses of an all-out frontal assault such as he had used at Arles, Charles was content to isolate the few remaining invaders in Narbonne and Septimania. The threat of invasion was diminished after the Umayyad defeat at Narbonne, and the unified Caliphate would collapse into civil war in 750 at the Battle of the Zab. It was left to Charles' son, Pepin the Short, to force Narbonne's surrender in 759, thus bringing Narbonne into the Frankish domains. The Umayyad dynasty was expelled, driven back to Al-Andalus where Abd al-Rahman I established an emirate in Córdoba in opposition to the Abbasid Caliph in Baghdad. In the northeast of Spain the Frankish emperors established the Marca Hispanica across the Pyrenees in part of what today is Catalonia, reconquering Girona in 785 and Barcelona in 801. This formed a buffer zone against Muslim lands across the Pyrenees. Historian J.M. Roberts said in 1993 of the Carolingian Dynasty: Before the Battle of Tours, stirrups may have been unknown in the west. Lynn Townsend White Jr. argues that the adoption of the stirrup for cavalry was the direct cause for the development of feudalism in the Frankish realm by Charles Martel and his heirs. Historical and macrohistorical views The historical views of this battle fall into three great phases, both in the East and especially in the West. Western