Odo, with his remaining nobility, fled to Charles Martel, seeking help. Charles was campaigning on the Danube when news reached him. Martel had a seasoned professional infantry which had campaigned with him for many years and force-marched his army towards Acquitaine. In addition to the levies of militia the Franks normally called up to buttress their forces, he formed an army of Gauls and Germans approximately 30,000 strong. The invading forces, having no reason to believe the Franks were anything more than one of the various barbarian tribes that had ravaged Europe after Rome's fall, failed to scout their strength in advance. They also misjudged Charles Martel, who was determined to prevent the expansion of the Caliphate over the Pyrenees into the heart of Christian Europe. This was a disastrous mistake which led to the defeat of Abdul Rahman in 732 (114 AH) near Poitiers, south of the Loire River.