The Umayyads had already taken over the southern coast of the Mediterranean, but it was their presence in the Iberian Peninsula that put them up against the borders of Aquitaine, whose Christian duke, Odo the Great, prepared to ensure the stability of his borders. Anticipating the potential conflict, he left his capital of Toulouse to gather military support. When the Umayyad army under Malik al-Khawlani besieged Toulouse, Odo was away.
Odo tried to gather help from Charles Martel, but "The Hammer"—who is often given credit for protecting the Christian West from the Muslim East—refused Odo, preferring to take a "wait and see" attitude about the spread of Islam. (To be fair, Odo and Charles were rival rulers, not friends, so Charles may have been happy to see his southern neighbor get weakened.)
The siege lasted three months before Odo returned with his gathering of Aquitanian, Frankish, and Gascon troops. (The Frankish troops were not likely part of Charles Martel's people; there were Franks living closer to Odo's territory who were not necessarily formally part of the Carolingian culture.) The Umayyad army had grown overconfident after three months of no opposition, so they had minimal outer defenses, making Odo's attack unexpected and hard to counter, especially when folk from inside Toulouse joined the fight. The Umayyads scattered, al-Khawlani died very soon afterward, and no secondary attempt on Toulouse was made.
Odo claimed (in a letter to Pope Gregory II, who like the caliphate was also focused on spreading his chosen faith, though with a less-warlike approach) that he had killed 375,000 Saracens and lost only 1500 men. Odo was praised as a champion of Christianity and received gifts from Gregory.
Eleven years later, however, Charles Martel could no longer "wait and see" when the Umayyads tried another surge into Western Europe, resulting in the Battle of Tours, which happens to be our next topic.