Through the influence of Æthelberht, his nephew Sæberht of Essex also converted, as did Rædwald of East Anglia, although Rædwald also retained an altar to the old gods. In 601 Pope Gregory sent additional missioners to assist Augustine. Among them was the monk Mellitus. Gregory wrote the "Epistola ad Mellitum" advising him that local temples be Christianized and asked Augustine to Christianize pagan practices, so far as possible, into dedication ceremonies or feasts of martyrs in order to ease the transition to Christianity. In 604 Augustine consecrated Mellitus as Bishop of the East Saxons. He established his see at London at a church probably founded by Æthelberht, rather than Sæberht. Another of Augustine's associates was Justus for whom Æthelberht built a church near Rochester, Kent.