No written Anglo-Saxon sources claim that Cissa was ever king. The 8th-century chronicler Bede stated that Ælle was the first king to have held "imperium", or overlordship, over other Anglo-Saxon kingdoms, but he makes no mention of Ælle's sons. The earliest source that does state that Cissa was king is that of the Anglo-Norman chronicler, Henry of Huntingdon, who wrote between 1130 and 1154, and clearly used his imagination to fill out gaps in the historical record. Henry of Huntingdon derived a lot of his information from Bede. The 13th-century chronicler Roger of Wendover used Henry's work as his main source and it is probable that both Henry and Roger had access to information from manuscripts and oral sources now lost. Both Henry of Huntingdon and Roger of Wendover provide extended versions of the three "Anglo-Saxon Chronicle" entries relating to Ælle and his sons. It is assumed by both authors that Ælle was succeeded by his "son" Cissa - as is the alleged date of this "succession".