Peasmarsh church is essentially Norman, but was greatly enlarged in the 13thc. It has a W tower, an aisled nave with three-bay arcades, and a large square-ended Early English chancel. The main Norman feature is the chancel arch.

Neither the manor nor the church is mentioned in 1086. The church is mentioned in the confirmatory charter of Count Henry of Eu, recording what his grandfather Count Robert of Eu (d.c.1090) gave soon after the Conquest to a prebend of the collegiate church of St. Mary-in-Castro, Hastings. The stag relief was uncovered during the restoration project of 1926.

The two reliefs reset on the S side of the chancel are of dark brownish-red iron-sandstone, while the bird relief in the NE buttress is in a lighter stone, probably also sandstone. The NE buttress is probably 14thc. in date.

The chancel arch appears to date from the late 11thc., a date suggested by its simple form and moulded imposts. The animal reliefs on the jambs may, like those on the exterior of the church, be reset. They are similar to a relief from Canterbury (CL 1051 64A), datedc.1080-90 by Deborah Kahn. The Peasmarsh reliefs have less internal modelling, but a generic similarity cannot be denied. The stag relief on the external buttress can be compared with a panel from Sainte-Paix, Caen (Mus. de la Soc. des Antiquaries de Normandie), also depicting a stag, and dated c. 1060-80 by Maylis Baylé. The Sainte-Paix stage is much more schematised, with less modulated contours, but again a generic resemblance is obvious.