 Eadbald 's influence was less than his father 's , but Kent was powerful enough to be omitted from the list of kingdoms dominated by Edwin of Northumbria . Edwin 's marriage to Eadbald 's sister , Æthelburg , established a good relationship between Kent and Northumbria which appears to have continued into Oswald 's reign . When Æthelburg fled to Kent on Edwin 's death in about 633 , she sent her children to Francia for safety , fearing the intrigues of both Eadbald and Oswald . The Kentish royal line made several strong diplomatic marriages over the succeeding years , including the marriage of Eanflæd , Eadbald 's niece , to Oswiu , and of Eorcenberht to Seaxburh , daughter of King Anna of East Anglia . 
