“A victorious line of march had been prolonged above a thousand miles from the rock of Gibraltar in Spain to the banks of the Loire in France; the repetition of an equal space would have carried the Saracens to the confines of Poland and the Highlands of Scotland; the Rhine is not more impassable than the Nile or Euphrates, and the Arabian Fleet might have sailed without a naval combat into the mouth of the River Thames. Perhaps the interpretation of the Qur’an would now be taught in the schools of Oxford, and her pulpits might demonstrate to a circumcised people the sanctity and truth of the revelation of Muhammed.”
Edward Gibbon, Decline and Fall of the Roman Empire
Charles Martel, “The Hammer”, led a life of conflict. An illegitimate son of Pepin of Herstal, Mayor of the Palace and the true power behind the Merovingian puppet kings, after the death of his father he had to fight his father’s legitimate offspring who sought to deprive him of any share in his father’s inheritance. Fortunately for Charles a streak of military genius ran through him, and he won battles against the odds, using force multiplying stratagems, including feigned retreats, and attacking in the middle of the day when armies of his time normally took a siesta. By 717 he was in control of Neustria, showing mercy unusual for his day in letting his defeated adversaries live and treating them with kindness.
The 28 year old ruler now entered a round of endless wars with neighboring kingdoms, gradually extending his power, and building up a professional force of infantry to supplement the peasant levies that made up the vast bulk of most Frankish armies.
A friend and patron of Saint Boniface, he also began the alliance between the rulers of the Franks and the Popes. He contributed much land to the Church, but roused ecclesiastical ire when he took some back to support his troops. He might have been excommunicated if both Church and State had not suddenly confronted a common foe.
In 711 the forces of Islam began the conquest of Spain, helped along by Christian traitors. Within a decade almost all of Spain had fallen, with small proto-kingdoms of Spaniards clinging to a precarious independence in the mountains of northern Spain. Mohammed had died less than a century before in 632, and in that intervening period Islam had conquered the Middle East, northern Africa and seemed poised to do the same in Europe against the petty Christian kingdoms that specialized in ceaseless internecine war, seemingly weakening themselves before their Islamic foes lifted a finger.
With Spain subdued, Muslim raids into what is now France became common. In 732 Abd-al-Raḥmân, governor of Muslim Spain, led a predominantly cavalry army of 25,000 men north on a great raid beyond the Pyrenees, perhaps the prelude to a war of conquest.