 Cedd built monasteries at Tilbury in the south and at Ythancæster, where there was an old Roman fort, at what is now Bradwell-on-Sea, in north-east Essex.Sigebert was assassinated by his own thegns and was succeeded by the pagan Swithelm of Essex.Cedd persuaded him to accept the faith and, according to Bede, his baptism by Cedd took place at Rendlesham, in the presence of King Æthelwold