Chadwell St Mary is a parish in the Unitary Authority of Thurrock, a mile to the N of Tilbury and 2 miles E of Grays. The church, in the centre of the old settlement, now stands at a busy crossroads where the roads to Tilbury, Grays and Orsett meet. It consists of a chancel, nave and W tower, with a 19thc addition on the S side, away from the road, that covers the S doorway. The nave, with S doorway and the remains of the N doorway above the present 13thc entrance is early 12thc. The chancel belongs to the 14thc and the tower was built c.1500. Construction is of flint rubble with some ragstone and Reigate dressings.

Chadwell was held as a manor of 2 hides by Aelfric in 1066 and by Hugolin from the Bishop of London in 1086. A priest was recorded at both dates. A smaller holding of 20 acres, held by Grim the Reeve, seems irrelevant to our purposes. Following Wright (1831), the earliest notice of the manor after Domesday was in c.1250, when it was held from the Bishop of London by a family called de Wokinden, who also held the advowson of the church. It later passed to the Haltons, and in the 15thc to John de Bois and then to Nicholas de Rykhill.

The extra decoration given to the N doorway is explained by the fact that is was the main entrance from the village street. The geometry of the rere-arch of this doorway indicates that the chip-carved outer parts are in their original position.