In 711 Umayyad armies crossed the Strait of Gibraltar and conquered Visigothic Spain within a few years. Raiding columns pushed over the Pyrenees into what is now southern France. In 732 (sources also say 733) the governor of al-Andalus, Abd al-Rahman al-Ghafiqi, marched north with a large force toward Tours, site of the wealthy monastery of Saint Martin.

The Frankish mayor of the palace, Charles Martel, positioned his army of heavy infantry on high ground between Tours and Poitiers. The disciplined Frankish foot soldiers met and broke the repeated charges of the Umayyad cavalry in a tight defensive formation. Al-Ghafiqi was killed and the Umayyad army withdrew. It was after this victory that Charles earned the byname 'Martel' (the Hammer).

The battle's true scale is debated. Some historians have treated it as a turning point that decided the fate of civilisations; most modern scholars are more cautious — noting that the Umayyad operation may have been a raid for plunder, and that internal problems in Spain would have halted the expansion anyway. The outcome, however, is clear: the advance of Islam into the northern interior of Western Europe ended here.

Its indirect effect was more lasting: the victory legitimised the dynasty of Charles Martel and, after him, his son Pepin and grandson Charlemagne. That line opened the way to the rise of the Carolingian Empire in the west of the continent.