4) Charles Martel
Charles Martel (“The Hammer“) was Duke and Prince of the Franks from AD 718 until his death in AD 741. He was the grandfather of Charlemagne, and was himself a far more significant figure in the grand scheme of mankind than historians generally ascribe. During the 8th century, Muslim armies under the command of the Umayyad dynasty (an empire rivaling ancient Rome in power and size) were invading Europe both in the east (through Anatolia) and in the West (through the Iberian peninsula). All of North Africa and Spain had already fallen to the forces of the caliphate when they entered France and were halted at Tours by the brilliance, tenacity, and resolve of the de facto King of the Franks — Charles the Hammer.
If not for this victory, the forces of the Islamic Caliphate would have easily conquered the rest of Europe (and with it, all of Christendom), forging a very different future than the one we currently experience. Western civilization, and the future propagation of Christianity in the world, hinged on the outcome of this pivotal event and the prince who delivered victory for his people.
“It was under one of their ablest and most renowned commanders, with a veteran army, and with every apparent advantage of time, place, and circumstance, that the Arabs made their great effort at the conquest of Europe north of the Pyrenees.” – Edward S. Creasy (speaking about the enormity of the odds against Charles’ victory at Tours).