Architectural Features
Possibly a foundation of the C5, a church is first mentioned on the site in 1173, and was probably dedicated to St.Illtyd by this time. In the C19 the church fell into disrepair, and was rebuilt in 1867-8 retaining the same plan and some of the medieval fabric. The architect was David Vaughan of Bonvilston, who had built a new town hall in Bridgend. It is likely that the Samuel Gibbon family of Trecastle were benefactors, as the contemporary stained glass windows were provided by them. They may also be represented by 2 small head bosses, a man and a woman, on the hoodmould of the west window. Parts of the north and south walls and the C15 chancel arch were retained from the earlier church, along with the decorated C15 font, which has similarities with those at Pyle and Llantrisant. Two church bells also survive from the earlier building, of C15 and C17 dates. The vestry was added in 1933.
Exterior
Small church with nave. West bellcote, south porch, chancel and north vestry. Constructed of coursed rubble with red banding or individual stone blocks under slate roofs. Bathstone quoins and dressings, raised copings and cross finials. Pointed arched windows with hoodmounds; single trefoiled lancets or plate tracery windows with 2 or 3 trefoiled lights. The west end has a 2 light window with large circle under the arch, and small quatrefoils in the spandrels. The end bosses of the hoodmound bear the heads of a man and a woman.
The west bellcote is supported on a corbelled relieving arch. Stepped sides and gabled roof to bell chamber, which contains 2 trefoiled openings for the bells.
The south side of the nave has a gabled porch with a steep pitch offset to the left. Chamfered pointed arched entrance with late C20 decorative steel gates. The porch which has a quarry tiled floor, and a sun-dial is high up on the outside. Single light to left of porch. Two 2 light windows to right, each with a quatrefoil in a circle under the arch. The chancel has continuous bands of red stone and contain 2 single lights
The east window is 3 light with a large circle containing a cinquefoil. The later lean-to vestry on the north side of the chancel has 2 short pointed windows to the north in the heavy surrounds, and a pointed doorway in the west end with planked door. The north side of the nave has a single trefoiled light offset to the left, probably respecting the medieval arrangement.
Interior
A pointed arched doorway leads into the nave which has a scissor-braced
roof. The small pointed chancel arch of grey stone has C15 dressings, 3 orders
of mouldings and narrow attached shafts to the interior jambs with rounded,
fluted caps. The nave has a central aisle flanked by benches with curved arm
rests, and a coloured quarry tile floor. C15 octagonal font to southwest with
chip-carved decoration. 
The south and northeast faces depict two stylised trees, whilst the east face bears two chip-carved circles, one above the other. The remaining sides have large rosettes. Octagonal wood paneled pulpit to left of chancel arch.
Scissor-braced roof to chancel. Choir stalls to each side with wood panelled
fronts decorated with blind vestry. The east window has brightly coloured
stained glass depicting the Nativity, Crucifixion and Resurrection by John Bell
of
The south windows of the chancel contain similar stained glass, bearing the heraldic emblems of the Samuel Gibbon family, a shield to the left and a boar's head to the right.
In the floor of the chancel, between the choir stalls, is an Elizabethan tomb
stone dedicated
to William Gibbon of Trecastle and dated 1584. A cast iron grave marker is set
into the wall at the southwest corner, and is dedicated to a later William
Gibbon (d1759), and bears a large heraldic shield in relief.
To the right of the vestry door is a stone panel dedicated to the Rev. Griffith Griffiths of Eckington, Worcestershire (d 1812). He was rector of the parish but mainly absentee, the memorial dedicated by those 'who took pleasure in his acquaintance'. Between the south windows of the chancel is a marble wall monument to Robert Savours of Trecastle (d 1818) and other members of his family.
A brass plaque over the vestry door is to Private William Lewis who died in the Boer War in 1901. On the north wall of the nave is a large marble tablet to Arthur Jenkin Richards, son of Rev. David Richards, who was killed in World War I.
Listed
Listed as a church retaining medieval fabric, which was rebuilt by a
significant
Reference
Newman. John. The Buildings of
Additional historical information supplied by Mr.David Francis