The church was founded in the twelfth or thirteenth century. The correct name of the settlement in Welsh meant “Mary’s church near the forest” (Llanfair Is Coed) and referred to the forest of Wentwood, which in the time of the Gwent kingdom separated the then territorial units Gwent Is Coed from Gwent Uwch Coed. In 1746, the porch was added to the church on the south side, and in the 19th century, the entire building underwent a thorough Victorian modernization.
The medieval church was a small, rural building consisting of a nave rectangular in plan and a four-sided chancel in the east. At that time, it probably did not yet have a sacristy on the north side of the chancel and a porch on the south side of the nave. The entrance for the congregation was placed in the center of the southern wall of the nave, additionally the parson could enter through the southern portal of the chancel. The interior was probably traditional for rural Welsh parish churches, and was covered with an open, wooden roof truss.
Salter M., The old parish churches of Gwent, Glamorgan & Gower, Wolverhampton 2002.
Website wikipedia.org, Llanvair Discoed.