One of a line of Anglo-Saxon churches with St Peter's and St Paul's to the west and St Pancras to the east established circa 620 by King Eadbald. Probably a funerary church. According to Goscelin writing at the end of the 11th century, St Mary's Church was used for important burials. These included the founders King Eadbald and Queen Emma, together with their successors, including Lothar and Wihtred and many abbots. About 1050 Abbot Wulfric built a tower possibly with the intention of linking St Mary's Church with that of St Peter and St Paul. This involved the partial demolition of both churches. With the death of Wulfric in 1061 the project was left unfinished although the ruined crypt is extant together with some fabric belonging to the church of St Mary. In 1073 Abbot Scolland demolished the remainder of St Mary's prior to building the abbey, the ruins of which can be seen today.