Abingdon Abbey was a Benedictine monastery also known as St Mary's Abbey located in Abingdon, historically in the county of Berkshire but now in Oxfordshire, England.HistoryThe abbey was supposedly founded in 675 either by Cissa, viceroy of Centwine, king of the West Saxons, or by his nephew Hean, in honour of the Virgin Mary, for twelve Benedictine monks.Endowed by successive West Saxon kings, it grew in importance and wealth until its destruction by the Danes in the reign of King Alfred, and the sequestration of its estates by Alfred because the monks had not made him a sufficient requital for vanquishing their enemies. By the 950s the abbey was in a decayed state, but in about 954 King Eadred appointed Æthelwold, later Bishop of Winchester, abbot. He was one of the leaders of the English Benedictine Reform, and Abingdon then became the second centre of the Reform (after Glastonbury). There is a collection of 136 charters granted to this abbey by various Saxon kings, and the Chronicle of the Monastery of Abingdon was written at the Abbey in the 12th century.