St Derfel's Church, Llandderfel, first mentioned in documents of 1254, is famous as the cult centre of St Derfel (or Derfyl Gadarn), whose feast day is April 5th. A life-sized medieval wooden statue, with traces of paint, known as Ceffyl Derfel (Derfel's horse), is located in the north porch, along with a wooden staff. Ceffyl Derfel, now headless, is said to be a stag, and was reputedly once positioned at the feet of a life-sized wooden effigy of St Derfel, dressed in full warrior armour and carrying the wooden staff. The effigy was the focus of a significant pilgrimage cult to St Derfel. In 1538 Cromwell's commissionary for the Diocese of St Asaph claimed that the people had such confidence, hope, and trust in St Derfel that they came on daily pilgrimage to visit the effigy, some with oxen or horses, and some with money. He reported that five or six hundred pilgrims had made offerings on that year's feast day. A legend stated that the effigy would one day burn down a forest. Cromwell therefore ordered it to be taken to London and used to light the pyre of a Jesuit priest, Father John Forest, confessor of Catherine of Aragon, who was burned alive for denying the supremacy of King Henry VIII as head of the Church. According to contemporary reports, the effigy was carried into the market place by eight men, with three executioners holding it in ropes, in the manner of a condemned criminal. The following verse was reputedly set up in great letters upon the gallows: 'David Darvell Catheren, as saith the Welshmen, fetched outlaws out of Hell. Now is he come with spere and shilde in harness to burn in Smithfeilde, for in Wales he may not dwell'. Consequently the effigy and its fate quickly became part of popular contemporary folklore. Cefyl Derfel remained in the church, but was reportedly decapitated in 1760 on the orders of the rural dean. In this period the statue is said to have been carried to Bryn Saint (NPRN 43830 ) in procession every Easter Tuesday, where it was used as a makeshift fairground ride.

Ffynnon Derfel (NPRN 32376) is located some 350m north-west of the church. The churchyard is curvilinear. The main entrance is via a lych gate (NPRN 43843) in the east corner of the boundary. An entrance on the south side was blocked in 1822. A hearse house (NPRN 43871) was formerly situated immediately inside the east churchyard boundary. It incorporated carved timbers thought to derive from the church. These were incorporated into the lych gate when the hearse house was demolished.

The church is a Grade I listed building, considered a well-preserved example of a late medieval building, retaining good original external character and interior detail. The fact that it was rebuilt in the fifteenth century, an unusual occurrence in Merioneth, is probably accounted for by the wealth generated by the popularity of its patron saint. The building sits on a wide, 1m high foundation plinth, which may reflect the pre-sixteenth century building. It consists of a continuous nave and chancel, north porch, south vestry (originally south porch) and west bellcote. The roof retains its original arch-braced collar trusses, with six bays to the nave two to the chancel. The trusses have cusped quatrefoil and trefoil decoration above the collars, which have foliated bosses to the centres. The chancel roof is canted and panelled with moulded members having foliated bosses at their junction. The rood screen dates to the mid-fifteenth century. It has nine bays with cusped four-centred arches, four on each side of a central opening. It has undergone various restorations. There are three windows in the north and south walls, each with three lights. The east window is similar, but with four lights. The north and south porches are thought to have been added in the seventeenth century. In 1729 wall paintings were noted, depicting the King's Arms, Creed, Lord's Prayer and other selected sentences. The oak roof was damaged by fire in 1758. A small portion of it was made into a chair, presently situated in the sanctuary, but most of it was removed to Plas Newydd, Llangollen (NPRN 27760). In the eighteenth century the rood loft was removed and the eastern parapet was used as part of a west gallery. Victorian wall paintings are noted in the chancel. In 1870 this was replaced above the old screen but turned around to face west. The church was restored in 1870. The pulpit dates to this time. The west door was blocked sometime after 1870, and a window was inserted. In 1921 the church was re-pointed, a drainage trench was dug, and the west end of the nave floor was replaced. In 1954 the heating system in the south porch was replaced.

Sources include:
Beverley Smith, J, Beverley Smith, Ll, 2001, History of Merioneth II, 344-347
Gwynedd Archaeological Trust, 2000, Historic churches of Gwynedd: gazetteer, 391
www.people.bath.ac.uk, 'Three Saints Two Wells and a Parish' by Tristan Grey Hulme
www.churchinwales.org.uk
Richard Suggett, Painted Temples: Wallpaintings and Rood-screens in Welsh Churches, 1200–1800, (RCAHMW 2021), pp. 128, 222, 223.

RCAHMW, 2021