The church originally had an “early English” nave, much lower than the present one, and also aisles, as shown by the small thirteenth century narrow lancet windows at the western end of the present aisles. The oldest part of the present church are these windows and the massive arches supporting the central tower.
The nave is late 14th century and in the perpendicular style. It was raised on its slender pillars around the fourteenth to fifteenth century when a clerestory was added. (A clerestory is the upper part of the wall, in this case in the nave, of a large church, which contains a series of windows, above the aisle roofs). The slender arches of the nave contrast with the low, pointed thirteenth century early English tower arch, through which the chancel is accessed.
Above and to the right of this arch, in the east wall of the nave, is a blocked-off doorway leading to the ringing chamber, with descending steps now ending in mid-air. These originally gave access to a rood screen, which held a cross. This was dismantled during the reformation. It was used for preaching. Until the 19th century there was a wooden pulpit to the left of the screen.
The north aisle contains an early Norman or possibly Saxon font, discovered in the churchyard at the beginning of the nineteenth century and placed in its present position.
The most easterly window on the north wall, above the remembrance table, contains glass from Llantilio Court.
The left shows the coat of arms and an inscription in memory of Sir David Gam, knighted by King Henry V, when Sir David was mortally wounded at the battle of Agincourt. Sir David lived at nearby Hengwrt, a house which was demolished in 1459. He is reputed to have been Shakespeare’s Fluellen, but the dates are inconsistent. The right side of the window is in memory of William Herbert, Earl of Pembroke, who was also connected with the Llantilio estate.
The middle window of the south wall marks the site of the former South porch. Normal entry to the nave is now through the west porch, which contains the parish chest. This dates to 1538 and housed registers, vestments and plate. It is constructed of plain oak and is 11ft. long with three locks – the vicars and the two church wardens held the keys to open it.
This is a large church for such a small village and it has been suggested that the Bishop used it as a sort of cathedral as he progressed between manors collecting tithes.