We can’t know Charles’ state of mind as he made his way home after the Spanish debacle in 778, but you can be sure he was not happy. What would have been a long and difficult journey home was made so much worse by the massacre in the Pyrenees. He must have been angry, frustrated, and saddened as the miles passed by and the weeks elapsed. At some point in the late summer, but definitely not before September1.The Roncevalles ambush occurred on August 15, he had made it as far as Auxerre, which is almost 500 miles from Roncevalles. It was at Auxerre, as he was “demobilising the rest of the troops,”2.Revised Royal Annals, year 778, King, p. 114. that the king received word that the Saxons were again in revolt.
This would not have been surprising. As we’ve seen, Franks and Saxons had been fighting for generations, and while the Franks usually held the upper hand in battle, the Frankish armies withdrew to Francia after combat. That gave the Saxons the opportunity to regroup, foment rebellion, and launch counterattacks. Prior to the Spanish expedition, however, King Charles had determined to complete the conquest and conversion of the Saxon people, and so he could not let this latest insurrection go unpunished, no matter how late in the year, or tired the army.