In 845 Charles the Bald signed a treaty with Pippin II of Aquitaine, recognizing Pippin as king of Aquitaine in exchange for Pippin's relinquishing of northern Aquitaine (the County of Poitiers) to Charles. The Aquitanians, now dissatisfied with Pippin, asked Charles to topple him in 848. The following year Charles received Toulouse from Frédelon, the count of Toulouse recently appointed by Pippin, and Charles confirmed Frédelon as count of Toulouse. Aquitaine soon submitted to Charles; in 852 Pippin was imprisoned by the Basques and handed over to Charles (who placed him in a monastery).