The Archbishop of London, Guithelinus, crosses to Little Britain to appeal for help from Aldroenus, “the fourth King after Conanus,” citing their common blood, the Britons’ desperate need for help since Maximianus colonized Little Britain with all the best British soldiers, and the glory of wearing the crown of Constantine and Maximianus (124). Due to Britain’s declining fortunes, Aldroenus refuses the offer but agrees to send his brother Constantine and 2,000 soldiers to “free the country from this barbarian invasion” (125).

Constantine sails with his forces to Britain and defeats the enemy. He is made king and given a noble wife with whom he has three sons—Constans, Aurelius Ambrosius, and Utherpendragon. Constantine sends Constans to become a monk. However, after Constantine is assassinated (and his brothers too young to assume the throne), a local leader called Vortigern convinces Constans to abandon his monastic orders and become king. Having no knowledge of how to rule, Constans defers to Vortigern, who plots to depose Constans and seize the crown for himself. He places Picts in Constans’ retinue and provokes them to assassinate Constans. Vortigern pretends to be distraught and has the assassins decapitated. Though some suspect Vortigern of orchestrating the assassination, others accept him.