These politics displeased the Basques, and in 787 or 789 Chorson was captured by Odalric "the Basque", probably son of Duke Lupus, who forced Chorson into an agreement which Charlemagne considered so shameful that he replaced him by the Count William in 790.
See poliitika pahandas baske ja aastast 787 või 789 on teada, et Corso püüti kinni arvatavasti hertsog Lupo poja Odalric "Baski" poolt, kes sundis Corso kokkuleppele, mida Karl Suur pidas nii häbiväärseks, et asendas ta aastal 790 krahv Guillaume'iga.