The Abbey of Bury St Edmunds was once among the richest Benedictine monasteries in England, until the Dissolution of the monasteries in 1539. It is in the town that grew up around it, Bury St Edmunds in the county of Suffolk, England. It was a centre of pilgrimage as the burial place of the Anglo-Saxon martyr-king Saint Edmund, killed by the Great Heathen Army of Danes in 869. The ruins of the abbey church and most other buildings are merely rubble cores, but two very large medieval gatehouses survive, as well as two secondary medieval churches built within the abbey complex.
When, in the early 10th century, the relics of the martyred king, St Edmund, were translated from Hoxne to Beodricsworth, afterwards known as St. Edmundsbury, the site had already been in religious use for nearly three centuries. To the small household of Benedictine monks who guarded the shrine the surrounding lands were granted in 1020, during the reign of Canute. Monks were introduced from St Benet's Abbey under the auspices of the Bishop of Elmham and Dunwich. Two of them became Bury's first two abbots, Ufi, prior of Holme, (d. 1044), who was consecrated abbot by the Bishop of London, and Leofstan (1044–65). After Leofstan's death, the king appointed his physician Baldwin to the abbacy (1065–97). Baldwin rebuilt the church and reinterred St Edmund's body there with great ceremony in 1095. The cult made the richly endowed abbey a popular destination for pilgrimages.
The abbey church of St Edmund was built in the 11th and 12th centuries on a cruciform plan, with its head (or apse) pointed east. The shrine of St Edmund stood behind the high altar. The abbey was much enlarged and rebuilt during the 12th century. At some 505 feet long, and spanning 246 ft across its westerly transept, Bury St Edmunds abbey church was one of the largest in the country. It is now ruined, with only some rubble cores remaining, but two other separate churches which were built within the abbey precinct survive, having always functioned as parish churches for the town. St James's Church, now St Edmundsbury Cathedral, was finished around 1135. St Mary's Church was first built around 1125, and then rebuilt in the Perpendicular style between 1425-35.