Constantine recognized the implicit danger in remaining at Galerius' court, where he was held as a virtual hostage. His career depended on being rescued by his father in the west. Constantius was quick to intervene. In the late spring or early summer of AD 305, Constantius requested leave for his son to help him campaign in Britain. After a long evening of drinking, Galerius granted the request. Constantine's later propaganda describes how he fled the court in the night, before Galerius could change his mind. He rode from post-house to post-house at high speed, hamstringing every horse in his wake. By the time Galerius awoke the following morning, Constantine had fled too far to be caught. Constantine joined his father in Gaul, at Bononia (Boulogne) before the summer of AD 305.