 Hearing of this the Black Prince ordered Hugh Calveley to invade Navarre from northern Castile and enforce the original agreement.Charles at once capitulated, claiming he had never been sincere in his dealings with Henry, and opened the passes to the Prince's army.Charles accompanied them on their journey but, not wanting to take part in the campaign personally, got Olivier de Mauny to stage an ambush in which Charles was 'captured' and held until the reconquest of Castile was over.