St Tudur's Church, located near the summit of Mynyddislwyn over 1,000 feet above sea level, is the parish church of Mynyddislwyn parish, formerly a very expansive upland parish in western Monmouthshire before the creation of further parishes in the later nineteenth century in response to dramatic demographic, social, and economic change brought about by extensive industrialisation. According to Bradney, the parish was sometimes called `Plwyf Tewdwr ap Howel?, either after the saint to whom the church is dedicated or to a vicar and patron of the church, Theodore Powell, whose gilded effigy (now lost) is supposed to have been in the church. The church was severely damaged by fire in 1800 and was largely rebuilt and expanded in 1819?20, excepting the tower to the west. The church was further restored in 1906?7 by E. M. Bruce Vaughan of Cardiff.

The church consists of a large nave without an architecturally delineated chancel (without external delineation or internal chancel arch) and a northern aisle extending nearly the entire length of the nave and separated from it internally by a four-bay arcade. The northern aisle has two pointed-arch-headed northern windows and an eastern window with Perpendicular style tracery. There is a similar, Perpendicular-style window in the eastern wall of the chancel. Both were probably added by Vaughan in 1907. The chancel window has stained-glass depicting Jesus appearing to the Marys at his empty tomb dating from c.1911 by Heaton, Butler & Bayne. To the south is another stained-glass chancel window with a text from Ecclesiasticus with abstract patterns dating from 1970 by John Petts. The nave also has two Perpendicular-style windows flanking the southern porch. The embattled western tower is of three storeys, delineated by string courses, with small rectangular windows and larger louvered openings to the ringing chamber. There is a small pointed-arched Perpendicular western doorway. The embattled stair turret at the north-eastern corner of the tower extends above the tower itself.

Internally, the nave is of bare stone with a wagon-roof ceiling dating from the 1906?7 restoration. The alter is at the eastern end of the chancel and a reading desk and panelled pulpit with tester are along the southern wall with a stage for the choir opposite. The small font has a square bowl with ogee undersides and a classically-shaped pedestal, and probably dates from the early nineteenth century. Around the walls are various monuments to local families and individuals dating from the eighteenth and nineteenth centuries (see Bradney for fuller transcriptions), including an unusual eighteenth-century painted wooden monument by the southern door.

Around the church are several large yew trees which formerly marked the churchyard boundaries. The lychgate is likely contemporary with the 1819?20 rebuild and is a symmetrical building of tooled stone and rubble with a pyramidal tiled roof, elliptical archways, iron gates and stone benches.

(Sources: Bradney, History of Monmouthshire: Vol. 5, The Hundred of Newport, ed. by Gray (Cardiff and Aberystwyth: 1993), pp. 139?44; Newman, Buildings of Wales: Gwent/Monmouthshire (Newhaven and London: 2002), p. 415; Cadw Listed Buildings Database)
A.N. Coward, 20.08.2018