The Battle of Tours (often called the Battle of Poitiers, but not to be confused with the Battle of Poitiers, 1356) was fought on October 10, 732 between forces under the Frankish leader Charles Martel and a massive invading Islamic army led by Emir Abdul Rahman Al Ghafiqi Abd al Rahman, near the city of Tours, France. During the battle, the Franks defeated the Islamic army and Emir Abd er Rahman was killed. This battle stopped the northward advance of Islam from the Iberian peninsula, and is considered by most historians to be of macrohistorical importance, in that it halted the Islamic conquests, and preserved Christianity as the controlling faith in Europe, during a period in which Islam was overrunning the remains of the old Roman and Persian Empires.
Franks, led by Charles Martel. Estimates of the Frankish army defending Gaul vary, but by most accounts were between 15,000 and 75,000. Losses according to St. Denis were about 1,500.
Muslims, between 60,000 and 400,000 cavalry, (most likely closer to the lower number) under Abd er Rahman; besides source differences, this army is difficult to estimate in size, since it was often fractured into raiding parties to carry out the pillaging and plundering of various richly cultured Frankish centers; however, the entire Muslim army was present at Tours by Arab accounts. During the six days he waited to begin the Battle, Abd er Rahman recalled all those columns raiding and pillaging, so that on the seventh day, when by both eastern and western accounts the Battle began, both armies were at full strength.
The Muslims in northern Spain had easily overrun Septimania, had set up a capital at Narbonne which they called Arbuna, giving its largely Arian inhabitants honorable terms, and quickly pacified the south and for some years threatened Frankish territories. Duke Odo of Aquitaine, also known as Eudes the Great, had decisively defeated a major invasion force in 721 at the Battle of Toulouse, but Arab raids continued, in 725 reaching as far as the city of Autun in Burgundy. Threatened by both the Arabs in the south and by the Franks in the north, in 730 Eudes allied himself with Uthman ibn Naissa, called "Munuza" by the Franks, the Berber emir in what would later become Catalonia. As a gage, Uthman was given Eudes's daughter Lampade in marriage to seal the alliance, and Arab raids across the Pyrenees, Eudes' southern border, ceased .
However, the next year, Uthman rebelled against the governor of al-Andalus, Abd er Rahman. Abd er Rahman quickly crushed the revolt, and next directed his attention against the traitor's former ally, Eudes. According to one unidentified Arab, "That army went through all places like a desolating storm." Duke Eudes (called King by some), collected his army at Bordeaux, but was defeated, and Bordeaux was plundered. The slaughter of Christians at the River Garonne was evidently horrific; Isidorus Pacensis commented that "solus Deus numerum morientium vel pereuntium recognoscat", 'God alone knows the number of the slain' (Chronicon). The Muslim horsemen then utterly devastated that portion of Gaul, their own histories saying the "faithful pierced through the mountains, tramples over rough and level ground, plunders far into the country of the Franks, and smites all with the sword, insomuch that when Eudo came to battle with them at the River Garonne, and fled." Eudes appealed to the Franks for assistance, which Charles Martel only granted after Eudes agreed to submit to Frankish authority.