From the content of the Chronicle, it is clear that the original author used the Historia ecclesiastica gentis Anglorum by Bede, which includes a similar chronological list, as a primary source of information. Other sources include some annals from Northumbria and Mercia, regnal lists, episcopal lists and genealogies. Our unknown author or authors may also have had access to a set of Frankish records for the late ninth century.
It has been suggested that the chronicler had an earlier set of West Saxon annals to work from. This would account for the frequency of references to events in Wessex up to about 754, but there is no way to verify this as the earlier annals are now lost. It is also believed that he included some items from oral tradition, and did not confine himself to written sources.
The original chronicler ceased writing in 891 or 892, and by 893 several copies of the manuscript had circulated throughout England. One of them came into the possession of Bishop Asser, who used it in his biography of Alfred the Great. Since clerics were the people most likely to have the skills of reading and writing, the manuscripts were primarily in the hands of ecclesiastics.
In most cases, the copies were expanded almost every year, becoming less of a history and more a record of contemporary events. In at least one instance, additional information on past events was added. Each copy was unique in what it had to offer, as what the new chroniclers considered significant enough to include in the record varied according to the individual and the circumstances.
One by one the chroniclers ceased to keep the manuscripts updated, until the last entry was recorded in 1154. By this time England was no longer wholly "Anglo-Saxon," since William the Conqueror had invaded in 1066 and a new aristocracy was in charge. While the chronicle had been written for centuries in Old English, the Norman rulers were now speaking Medieval French, and the language spoken by most people in England had begun to evolve into Middle English. The Anglo-Saxon language was fading, and Anglo-Saxon history was undergoing a metamorphosis into the history of the English.
