The only surviving lists of the kings of East Anglia are those written by mediaeval sources, such as William of Malmesbury. Nothing is known about any of the kings from 664 to 747, after which the succession and genealogy of the kings of East Anglia after this time is uncertain. The Vikings attacked Norfolk in 865 and four years later killed Edmund, the last king of the East Angles. Villages on the former island of Flegg with names such as Scratby, Hemsby and Filby provide evidence of Viking settlement: other place-names of Viking origin are scattered around Norfolk. Viking settlement is thought to have stimulated the growth of towns such as Norwich and Thetford. After Edward the Elder conquered East Anglia and ended Viking domination in c. 917, the region was absorbed into the kingdom of England.