East Angles during much of the Anglo-Saxon period. Its history is largely obscure: much information is based on mediaeval chronicles and often cannot be verified. The history of Norfolk, the northern half of the kingdom, cannot be distinguished from the rest of East Anglia during this period. East Anglia was first ruled by semi-historical kings from the Wuffings dynasty, who, according to the 9th-century Historia Brittonum of Nennius, descended to Wuffa of East Anglia from Wōden. In the Anglo-Saxon Chronicle, the most important historical source for the Anglo-Saxon period, only Rædwald of East Anglia and his successors Eorpwald, Anna, Æthelberht and Edmund the Martyr are mentioned. An important source of information is Bede's Historia ecclesiastica gentis Anglorum, which describes events during the reigns of several East Anglian kings, including Raedwald, the first king who is known by more than a name. 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. Mediaeval Norfolk At the time of the Norman Conquest, Norfolk formed part of the earldom of Harold I of England and offered no active resistance to William the Conqueror, who bestowed the earldom of East Anglia on Ralph de Gael. After the Revolt of the Earls in 1075, Earl Ralph's estates were forfeited and passed to Roger Bigod. Mediaeval Norwich The arrival of the Normans in 1066 led to the destruction of much of Anglo-Saxon Norwich. After Ralph de Gael rebelled against the king, a large part of the town was burned by the Normans in retribution. They then started to develop Norwich into a prosperous international port and a centre of Norman power. Norwich Castle was built by 1075. It was