When he contracted his alliance with the Duke of Aquitania, Charles Martel did not know against what enemies and perils he would soon have to struggle.
In the earlier years of the eighth century, less than a hundred years from the death of Mahomet, the Mussulman Arabs, after having conquered Syria, Mesopotamia, Egypt, and Northern Africa, had passed into Europe, invaded Spain, overthrown the kingdom of the Visigoths, driven back the remnants of the nation and their chief, Pelagius, to the north of the Peninsula, into the Asturias and Galicia, and pushed even beyond the Pyrenees, into old Narbonness, then called Septimania, their limitless incursions.

These fiery conquerors did not amount at that time, according to the most probable estimates, to more than fifty thousand; but they were under the influence of religious and warlike enthusiasm at one and the same time; they were fanatics in the cause of Deism and of glory.

"The Arab warrior during campaigns was not excused from any one of the essential duties of Islamism; he was bound to pray at least once a day, on rising in the morning, at the blush of dawn.

The general of the army was its priest; he it was who, at the head of the ranks, gave the signal for prayer, uttered the words, reminded the troops of the precepts of the Koran, and enjoined upon them forgetfulness of personal quarrels." One day, on the point of engaging in a decisive battle, Moussaben- Nossair, first governor of Mussulman Africa, was praying, according to usage, at the head of the troops; and he omitted the invocation of the name of the Khalif, a respectful formality indispensable on the occasion.
One of his officers, persuaded that it was a mere slip on Moussa's part, made a point of admonishing him.

"Know thou," said Moussa, "that we are in such a position and at such an hour that no other name must be invoked save that of the most high God." Moussa was, apparently, the first Arab chief to cross the Pyrenees and march, plundering as he went, into Narbonness.