Osbert de Clare

Osbert of Clare (died in or after 1158) was a monk, elected prior of Westminster Abbey and briefly abbot. He was a prolific writer of letters, a hagiographer and a forger of charters.

By 1138, he had reworked the vita Ædwardi regis of Westminster Abbey. He himself composed a Life of St Eadburh of Winchester for Pershore Abbey and a Life of St Æthelberht of East Anglia, dedicated to Gilbert Foliot sometime after 1148.

...
Wikipedia