A priory was founded on the site of St Basil's Church in 1105 by Robert de la Haye but was abandoned in 1235. The present fabric is principally fourteenth to fifteenth centuries and includes a nave and chancel with a large western tower and southern aisle. A free-standing fourteenth to fifteenth century chapel on the south side was demolished in1850. The medieval arcade, since replaced, was of heavy square pillars and low arches.

The south porch, nave arcade and windows were restored in 1878-9 by Habershon Fawckner & Co of Newport, while the south transept, the organ chamber, the chancel roof and possibly the nave and aisle roofs were restored in 1902-3 by C. Busteed Fowler of Cardiff.

The north-eastern chapel is of uncertain date, but was possibly built around 1800 as a burial place of the Morgans of Tredegar, similar to the chapel at Lower Machen. It was remodelled in 1916 for the 1st Viscount Tredegar, who died in 1934. It contains some particularly fine monuments from 1806 onward.

There are hatchments and related heraldry in the church associated with the Morgan family.

Sources include:
Cadw Listed Buildings. ALH 14/11/2012
Richard Suggett, Painted Temples: Wallpaintings and Rood-screens in Welsh Churches, 1200–1800, (RCAHMW 2021).

RCAHMW 2021