The church itself is one of the finest Norman buildings in England. Its massive crossing tower was rated "probably the largest and finest Romanesque tower in England" by Sir Nikolaus Pevsner. Fourteen of England's cathedrals are of smaller dimensions, while only Westminster Abbey contains more medieval church monuments.
The Chronicle of Tewkesbury records that the first Christian worship was brought to the area by Theoc, a missionary from Northumbria, who built his cell in the mid-7th century near on a gravel spit where the Severn and Avon rivers join together. The cell was succeeded by a monastery in 715, but nothing remaining of it has been identified.
In the 10th century the religious foundation at Tewkesbury became a priory subordinate to the benedictine Cranbourne Abbey in Dorset. In 1087, William the Conqueror gave the manor of Tewkesbury to his cousin, Robert Fitzhamon, who, with Giraldus, Abbot of Cranbourne, founded the present abbey in 1092. Building of the present Abbey church did not start until 1102, employing Caen stone imported from Normandy and floated up the Severn.
Robert Fitzhamon died at Falaise in Normandy, in 1102, but his son-in-law, Robert FitzRoy, the natural son of Henry I who was made Earl of Gloucester, continued to fund the building work. The Abbey's greatest single later patron was Lady Eleanor le Despenser, last of the De Clare heirs of FitzRoy. In the High Middle Ages, Tewkesbury became one of the richest abbeys of England.
After the Battle of Tewkesbury in the Wars of the Roses on 4 May 1471, some of the defeated Lancastrians sought sanctuary in the abbey, but the victorious Yorkists, led by King Edward IV, forced their way into the abbey, and the resulting bloodshed caused the building to be closed for a month until it could be purified and re-consecrated.
After the Dissolution of the Monasteries, the people of Tewkesbury saved the abbey from destruction in 1539: Insisting it was their parish church, which they had the right to keep, they bought it for the value of its bells and lead roof which would have been salvaged and melted down, leaving the structure a roofless ruin. The price came to £453.
The bells merited their own free-standing belltower, an unusual feature in English sites. After the Dissolution, the bell-tower was used as the gaol for the borough until it was demolished in the late 18th century.
The central stone tower was originally topped with a wooden spire, which collapsed in 1559 and was never rebuilt. Some restoration undertaken in the 19th century under Sir Gilbert Scott included the rood screen that replaced the one removed when the Abbey became a parish church.
The church's 17th century organ was originally made for Magdalen College, Oxford. After the Civil War it was removed to the chapel of Hampton Court Palace and came to Tewkesbury in 1737.
Flood waters reached inside the Abbey in severe floods in 1760, and again on 23 July 2007.