Tewin is a village in the East Hertfordshire district, 2 miles NE of Welwyn Garden City and 4 miles NW of Hertford. The church is SW of the village centre and is a flint rubble building with ashlar dressings. It consists of a nave with a 3-bay S aisle and a timber framed S porch, a chancel with a N vestry and a W tower with a small spire. Evidence for the 11thc. origins of the church survives in windows in the N and S nave walls, and these are the only features recorded here.

IN 1066 Healfdene, a thegn of King Edward, held the manor and when King William came to the throne he gave it to Healfdene and his mother for the soul of his second son Richard, who died while hunting in the New Forest. However, in the Domesday Survey Healfdene was holding Tewin from Peter de Valognes, the sheriff. The manor was assessed at 5 hides and a half. The advowson of the church passed with the manor, but in 1211 there was a dispute between Richard son of Godfrey de Tewin and Ralph son of Brian de Tewin who each held half a fee in Tewin. It was adjudicated in favour of Richard. Before 1246, the advowson was given by Alexander de Swereford to the monastery of St. Bartholomew, Smithfield and remained with that house until the Dissolution.

Based on visual evidence of the remaining windows the nave of the church dates form the late-11thc. The chancel was remodelled in the 13thc, when the S aisle was added too. The tower dates from the 15thc, the timber-framed S porch from the 16thc. and the vestry was added in 1903 by T. P. Atkinson. In 1864 the church was restored by F. Smith.

Both Bettley and the List Desciption agree that the windows are 11thc., on the basis on the N window exterior with its monolithic head and jambs.