The chancel is c.1230.
The S aisle was added to the nave c.1250, and the lower part of the tower was built in the late C13.
EXTERIOR Chancel N and S walls have 3 C13 lancets, heavily restored.
In the S wall there is a C13 pointed doorway with chamfered jambs, and to the W of it a low side window with a rounded head, probably widened from a lancet.
The nave N wall has three C14 windows, the eastern is pointed and of two trefoiled lights with a quatrefoil in the head.
The S wall has evidence for a blocked 3-bay C13 aisle.
The eastern bay has a large, C19 window in an C13 style.
The arcade is mid C13 and is of two chamfered orders on octagonal columns with moulded capitals and bases.
The middle bay appears to have been blocked in the C15, and the other two bays were blocked and the aisle demolished at an unknown later date, perhaps in the C18 when the S porch was built.
There is no W door, only a C13 lancet in the W wall.
INTERIOR The chancel arch is probably C14 and has two chamfered orders, the outer continuous, the inner on polygonal responds with moulded capitals.
The tower arch is of one chamfered order of the late C13.
The nave roof is C15 and has two king-post trusses with curved braces and traceried spandrels.
It sits on large head sop corbels, probably C14.
Also in chancel, a possibly C13 cupboard in the N wall
a recess behind the altar, possibly C14.
Royal arms of George I. Stained glass: some C14 fragments, some of it in situ, in the nave N windows.
HISTORY Shoebury (North and South) is mentioned in the Domesday book of 1086, but the church was not mentioned.
The church had been given to nearby Prittlewell Priory before 1170, although there is no surviving fabric of this date.
SOURCES Buildings of England: Essex , 704-5 RCHME Essex IV , 101-2, includes plan.
REASONS FOR DESIGNATION The church of St Mary the Virgin, Southend on Sea, Essex is designated at Grade II* for the following principal reasons: * Excellent surviving medieval fabric of the C13 and later. * Nave roof of the C15. * Good medieval fittings, including piscina, tiles and some fragments of glass. * The blocked C13 S aisle retaining the arcade is an interesting historical curiosity.