[4] Sources of information include the names of a few of the early Wuffing kings, mentioned in a short passage in Bede's Ecclesiastical History of the English People, written in the 730s.

Steven Plunkett relates that, according to the version of events as told in the Whitby Life of St Gregory, it was Paulinus who visited Edwin and obtained his promise to convert to Christianity in return for regal power.

[9] It is unclear whether, as Bede understood, Sigebert and Eorpwald were brothers, or whether they shared the same mother but not the same father, as was stated by the 12th-century chronicler William of Malmesbury.

According to the historian Barbara Yorke, Sigebert may have been a member of a different line of Wuffings who, as his rival, was forced into exile, in order to ensure that Eorpwald became king.

[12] In 627, Edwin undertook the conversion of the peoples of Northumbria, Lindsey and East Anglia[11] and at his prompting Eorpwald was, according to Bede, "persuaded to accept the Christian faith and sacraments".

[11] Following his baptism, Edwin's Northumbrian priests were in a position to be able to suppress pagan practices in Eorpwald's kingdom and convert the East Anglians.

[20] The conversion had the general political benefit of bringing the entire eastern seaboard from Northumbria to Kent, with the exception of Essex, under the dominion of Edwin and his Christian allies.

[23] At Sutton Hoo (near Woodbridge, in Suffolk) is the site of two 6th-7th century Anglo-Saxon cemeteries, where it is believed that members of Eorpwald's dynasty were entombed under large earth mounds.

Several East Anglian kings, including Eorpwald, have been suggested as possible candidates for the occupant of the burial site under Mound 1, discovered in 1939.

Martin Carver has speculated that historians could use regal lists and other sources of information to identify the occupants, whilst acknowledging that no material evidence exists to support the theory that Eorpwald or other members of his family are buried there.