In the Historia Brittonum written in the the early 9th century, Nennius mentions that a tomb with the inscription "Constantius the Emperor" still stood at the site. Some believe it was the tomb Constantius, father of Constantine the Great. Others believe it could be the tomb of Constantine (not that one) son of Magnus Maximus and Saint Helen.
In 1536 the building abbey was surrendered to King Henry VIII after the split with the Catholic church. All valuables were sold off and the church was left to decay.