Very little is known of the medieval church of St Mary, and nothing of the Anglo-Saxon building which may have preceded it.

The earliest part of the present building is the stump of the early 16th century W. tower. The rest of the church was rebuilt in brick, 1713-14, after the Siege of Colchester in 1648, later demolished (leaving only the tower) to make way for the present red brick structure designed by Sir Arthur Blomfield.<1>

The church stands in the SW angle of the walled town. W tower walls are stone with limestone dressings; upper stage is brick. The tower is mid-late C15 or early 16th, - lower two stages. The church was ruined in the siege of 1648 and rebuilt 1713-14, but was pulled down in the second half of the C19 and the present church built in 1872. The tower top stage was added in 1729. Tower has original windows and W. doorway.<2><3>

Morant was for a time the rector of this parish and records interesting details relating to the early C18 reconstruction. He records that the churchyard was levelled in 1714 and handsome gravel walls made around the church. The church had been rebuilt on a more humble scale than had originally been proposed, and proved inadequate for the aspirations of the Victorian congregation, and was demolished in 1872 except for the tower. The graveyard is historically more important than the church.<4><5>

Bettley & Pevsner record, 'Big Late Perp W. tower with diagonal buttresses and at the base a frieze of shields. Upper parts brick, 1729; the very top of 1911 by S. Gambier Parry. The rest of the church had been ruined in the siege of 1648. was first rebuilt by John Price 1713-14, and again (in brick) by A.W. Blomfield, 1871-2. Long nave with circular piers with elaborately and naturalistically carved capitals; this and the carving over the S. porch door by Earp. Circular clerestory windows. Shallow chancel with straight E end, N. vestry and organ chamber, and S. transept for children's seating.'<6>

Monument to John Rebow, d. 1699, whole figure, seated, very well carved.<6>

The discovery of graves, perhaps of the Middle-Saxon period, south of the surviving churchyard suggests that a pre-Conquest church stood on or near the site of the surviving building. (See MCC1650, MCC1651 and ECC670).<5>

The church, near the western postern in the town wall, lay within the soke acquired by the bishop of London between AD 998 and 1066 and was recorded in 1206.<7>

A watching brief was undertaken of two boreholes drilled through the floor at the western end of the church. One borehole encountered a 300m space beneath the floorboards, then a dry mid brown sandy loam which extended to an overall depth of 700mm. This material which appeared to be either backfill or make up sealed a further 800mm of probable backfill above a possible vault represented void reaching from 1.5m to 3m overall depth. The second borehole was abandoned at a depth of 0.8m where the drill hit solid masonry which included fragments of Kentish Ragstone.<8>

Foundations and tessellated pavement were found under the east end of St Mary's Church in 1871, shown on 1876 OS 1:500 map.<9>

Print by W.H. Oldmeadow (florit 1824) of St Mary at the Walls, Colchester.<10>

Closed 1978, now an arts centre.

Two digital photographs of St Mary's Church, taken in August 2016.<11>