Accession After an interregnum prompted by Eorpwald's assassination, Sigeberht returned from Gaul to become ruler of the East Angles. It is likely that he gained the kingdom by military means, because his prowess as a commander was later remembered. During his reign, part of the kingdom was governed by
Ecgric his 'kinsman', a relationship described by the Latin term
cognatus. This may mean that Ecgric was a son of Rædwald. However, Plunkett is amongst those that consider Ecgric to be the same person as Æthelric, named in the East Anglian tally (in the
Anglian collection) as a son of
Eni, Rædwald's brother. Whoever the pagan Ecgric was, Sigeberht had equal or senior power while he ruled, because the influence of his religious patronage was felt throughout his kingdom. Sigeberht's Christian conversion may have been a decisive factor in his achieving royal power, since at that time
Edwin of Northumbria (616–632 or 633) was the senior English king and he and
Eadbald, who ruled Kent, were Christian. Eadbald certainly had contacts with the Frankish rulers. After
Dagobert succeeded
Clothar II in Francia in 628, Sigeberht's emergence helped to strengthen the English conversion upon which Edwin's power rested. Sigeberht is likely to have encouraged the conversion of Ecgric, if he was not already Christian. Edwin's encouragement took shape in the marriage of his grand-niece
Hereswitha, sister of
Hilda of Whitby, to Æthelric, Rædwald's nephew. Hereswith and Hilda were under Edwin's protection and were baptised with him in 626.
Foundation of the East Anglian bishopric Bede relates that the East Anglian apostle
Felix of Burgundy came to England from
Burgundy as a missionary bishop and was sent by
Honorius,
Archbishop of Canterbury, to assist in establishing Christianity in Sigeberht's kingdom. William of Malmesbury had the later story that Felix accompanied Sigeberht to East Anglia. In either case, this dates Sigeberht's accession to around 629–630, because Felix was bishop for seventeen years, his successor
Thomas for five and Thomas' successor
Berhtgisl Boniface for seventeen – and Berhtgisl died in around 669. Sigeberht established the bishop's seat of his kingdom for Felix at Dommoc, claimed variously for
Dunwich or
Walton,
Felixstowe (both coastal sites in
Suffolk). If the seat was at Walton (as Rochester claimed during the 13th century), the site of Dommoc may have been within the precinct of a
Roman fort which formerly stood there.
Foundation of the East Anglian school Sigeberht secured the future of the Church in East Anglia when he established a school in his kingdom so that boys could be taught reading and writing in Latin, on the model that he had witnessed in Gaul. Felix assisted him by obtaining teachers of the kind who taught in
Kent. According to the
Life of Gregory the Great,
Paulinus of York, who from 633 to 644 was the
Bishop of Rochester in northern Kent, had been connected with Rædwald's court during the exile of Edwin.
Foundation of Cnobheresburg The allegiance of Felix to
Canterbury determined the Roman basis of the East Anglian Church, influenced along continental lines, though Felix's training in Burgundy may have been coloured by the teaching of the Irish missionary
Saint Columbanus in
Luxeuil. In around 633, perhaps shortly before
Saint Aidan was sent to
Lindisfarne from
Iona, the Irish royal hermit and missionary
Saint Fursey came to East Anglia from the
Athlone area, along with his priests and brethren. Sigeberht granted him a monastery site in an old
Roman fort called Cnobheresburg, usually identified as
Burgh Castle, near
Great Yarmouth. Felix and Fursey both effected a large number of conversions and established many churches in Sigeberht's kingdom. Bede records that Archbishop Honorius and Bishop Felix much admired the work of Saint Aidan of Lindisfarne and it is therefore likely that they also appreciated the tasks accomplished by Saint Fursey, whose community also lived according to the ascetic principles of
Irish Christianity. ==Abdication and martyrdom==