Although Karl Martell (also “Martel”), called “Charles the Hammer” (born 686, died 741) was Mayor of the Palace (“major domo”) of the kingdoms of the Franks, he is remembered for winning the Battle of Tours in 732, which saved Europe from the Emirate of Cordoba's expansion beyond the Iberian Peninsula. Martel's Frankish army defeated an Islamic army, which had crushed all resistance before it. The Muslims had previously invaded Gaul and had been stopped in their northward sweep at the Battle of Toulouse (721).
The Battle of Tours earned Charles the cognomen “Martel” for his victory. Many historians believe that had he failed at Tours, Islam would probably have overrun Gaul, and perhaps the remainder of Europe.
The Battle of Tours probably took place somewhere between Tours and Poitiers. The Frankish army, under Charles Martel, consisted of veteran infantry, somewhere between 15,000 and 75,000 men. Responding to the Muslim invasion, the Franks had avoided the old Roman roads, hoping to take the invaders by surprise. From the Muslim accounts of the battle, the Muslims were indeed taken by surprise to find a large force opposing their expected sack of Tours, and they waited for six days, scouting the enemy. On the seventh day, the Muslim army, consisting of between 60,000 and 400,000 horsemen attacked. The Franks defeated the Islamic army and the emir was killed. While Western accounts are sketchy, Arab accounts are fairly detailed that the Franks formed a large square and fought a brilliant defensive battle. The Muslims were not ready for such a struggle, and should have abandoned the loot that hindered them, but instead trusted their horsemen, who had never failed them. Indeed, it was thought impossible for infantry of that age to withstand armored mounted warriors. Martel managed to inspire his men to stand firm against a force that must have seemed invincible to them, huge mailed horsemen, who in addition probably badly outnumbered the Franks. But bickering between the Islamic generals caused the Muslims to abandon the battlefield, leaving Martel a unique place in history as the savior of Europe, and the only man to ever manage such a victory between such disparate forces. Martel's Franks, virtually all infantry without armor, managed to withstand mailed horsemen, without the aid of bows or firearms, a feat of arms unheard of in medieval history.
Although it took another two generations for the Franks to drive all the Muslim attackers out of Gaul and across the Pyrenees, Charles Martel's halt of the invasion of French soil turned the tide of Islamic advances, and the unification of the Frankish kingdoms under Martel, his son Pippin the Younger (also known as “Pepin the Short”), and his grandson Karl the Great (“Charlemagne”) prevented the Islamic armies from expanding over the Pyrenees.