and his three sons fought three battles: at Cymenshore in 477, one near the banks of Mercredesburne in 485 and lastly one at Pevensey in 491, where (the "Chronicle" claims) all Britons were slaughtered. The "Anglo-Saxon Chronicle" was originally compiled in Winchester, the capital of Wessex, and completed in 891. It was then distributed to various monasteries throughout the country for copying. The different versions were then updated periodically. The chronicle texts chart Anglo-Saxon history from the mid-fifth century until 1154. Before the Norman Conquest of 1066 the manuscripts were mainly written in Old English; post-Conquest the scribes tended to use Latin. The original "Chronicle" was commissioned during the rule of Alfred the Great over 400 years after Cissa, and historians regard the accuracy of the events and dates listed during the fifth century as questionable. The sources for the fifth century annals are obscure, however an analysis of the text demonstrates some poetic conventions, so it is probable that the narrative derived from an oral tradition, such as sagas in the form of epic poems. The "Anglo-Saxon Chronicle" was commissioned for a number of reasons, including propaganda—it provided genealogies of the kings of Wessex, showing them in a positive light. (Wessex had absorbed the Kingdom of Sussex, founded by Ælle, during the reign of Egbert of Wessex .)