 While Maxentius built up Rome 's defenses , Maximian made his way to Gaul to negotiate with Constantine . A deal was struck in which Constantine would marry Maximian 's younger daughter Fausta and be elevated to Augustan rank in Maxentius ' secessionist regime . In return , Constantine would reaffirm the old family alliance between Maximian and Constantius , and support Maxentius ' cause in Italy but would remain neutral in the war with Galerius . The deal was sealed with a double ceremony in Trier in the late summer of 307 , at which Constantine married Fausta and was declared Augustus by Maximian . 
