When London once more became the seat of a bishopric, Mellitus was chosen by Augustine to be Bishop of the See and the Church of St. Paul was founded as its Cathedral. He was driven from London by the heathen sons of King Sebert of Essex, in consequence of his refusal to give them the sacramental bread unless they consented to be baptised. He fled to Gaul but was recalled by St. Laurence of Canterbury, upon whose death, in AD 619, he succeeded to the Archbishopric of Canterbury, and died on 24th April AD 624. Of the last years of his life scarcely anything is known.