Byrhtferth (Old English: Byrhtferð; c. 970 – c. 1020) was a priest and monk who lived at Ramsey Abbey in Huntingdonshire (now part of Cambridgeshire) in England.
[3] Cyril Roy Hart also tentatively identifies him as the author of the verse Menologium preserved as a preface to a manuscript of the Anglo-Saxon Chronicle,[9][10] although Kazutomo Karasawa believes it more likely to have been written by an older contemporary.
[4] However, many scholars argue that these works were not written by Byrhtferth, but instead were a compilation of material by several writers in the late ninth and early tenth centuries.
[4] St John's College, Oxford MS 17 [13] contains several computistical works by Bede and Helperic, and a computus which includes the Latin Epilogus ("Preface") by Byrhtferth.
He also constructed a full-page diagram showing the harmony of the universe, and suggesting correspondences among cosmological, numerological, and physiological aspects of the world.