In the void left by the death of Rædwald, the first overlord who originated north of the Thames, the pagan Penda of Mercia emerged to challenge the pre-eminence of the new overlord (or bretwalda), Edwin of Northumbria. The reversion of East Anglia to rule by Eorpwald's successor, the pagan Ricberht, possibly due to Mercian influence, temporarily overthrew an important pillar of Edwin's authority. In contrast, two sons of Rædwald's brother Eni, who were both eager to renew their Christian alliances, made diplomatic marriages during this period: Anna, who was to become a devout Christian ruler, married a woman of East Saxon connection and his brother Æthelric married a Northumbrian princess, Hereswitha, who was Edwin of Northumbria's grand-niece. This marriage was probably intended to reinforce the conversion of East Anglia to Christianity. Ecgric was a member of the Wuffingas royal family, but his exact descent is not known, as the only information historians have is from Bede, who named him as Sigeberht's "cognatus" or 'kinsman'. The 12th century English historian William of Malmesbury contradicts Bede, stating that Sigeberht was Rædwald's stepson. The name "Sigeberht" is not of East Anglian, but of Frankish origin. Rædwald may have exiled his step-son so as to protect the inheritance of his son Ecgric, who was of his own blood-line. It has been suggested by Sam Newton that Ecgric may in fact be identical to Eni's son Æthelric, whose descendants became kings of East Anglia. Æthelric's son Ealdwulf ruled from about 664 to 713. After Ecgric's death, three other sons of Eni ruled in succession before Ealdwulf, an indication that Raedwald's line was extinct. Æthelric's marriage to Hereswith suggests that it was expected that he would rule East Anglia and he may have been promoted by Edwin before 632. Æthelric was apparently dead by 647, at which time Anna was already ruling and Hereswith had gone to Gaul to lead a religious life. It has therefore been argued that Æthelric and Ecgric were in fact the same person, a suggestion that is disputed by the historian Barbara Yorke, who notes that the two names are too distinct to be compatible.