The Anglo-Saxon Chronicle, According to the Several Original Authorities
Wikipedia: The Anglo-Saxon Chronicle is a collection of annals in Old English chronicling the history of the Anglo-Saxons. The original manuscript of the Chronicle was created late in the 9th century, probably in Wessex, during the reign of Alfred the Great (r. 871–899). Multiple copies were made of that one original and then distributed to monasteries across England, where they were independently updated. In one case, the Chronicle was still being actively updated in 1154.