This report describes excavations at the St Mary's Priory and cathedral church, Coventry, conducted between 1999 and 2003 as part of the Phoenix Initiative, Coventry's Millennium Project. The Priory was located on the site of a late Saxon Abbey whose benefactors were Leofric, Earl of Mercia, and his wife, Lady Godiva. Its church became a cathedral in the early 12th C AD and the priory grew to become one of the largest monastic communities in the region. It was suppressed on 15th January 1539 and the cathedral became the only one in the Kingdom to be destroyed as a result of dissolution. This excavation report describes the history of the buildings and then presents new discoveries about the cathedral, the monastic house, the service buildings and priory mill. Detailed studies of finds include chapters on floor tiles, apocalyptic paintings in the Chapter House, pottery, coins, leather, wood, glass and human bone.