John Flete was Prior and historian of Westminster Abbey. He died in 1466 and was presumably buried in the Abbey or cloisters although this is not recorded in the monastic account rolls. So his grave location is unknown. If Flete was his family surname, rather than one chosen when he joined the monastery, he could have been related to the London merchants of this name. He came to the Benedictine monastery at Westminster in 1420 and later held various offices including those of almoner, sacrist and warden of the manors of Queen Eleanor and of Richard II. After a fire he superintended the rebuilding of the dormitory (part of which is now the Library of the Abbey). He became Prior in 1456. His history of the Abbey was compiled in 1443 and this manuscript is in the Abbey library (MS.29). He gave gifts of vestments to the Church but none of these remain.
The illustration is a page from his manuscript.
Oxford Dictionary of National Biography 2004
Flete's History of Westminster Abbey edited by J. Armitage Robinson, 1909 (an English translation is available at the Abbey Library)