Llantilio Crossenny was a manor of the Bishops of Llandaff in the Middle Ages, and the site of their manor house can still be seen at Hen Gwrt. Their episcopal presence and the proximity of White Castle account for the 'exceptional scale' of the church. It is of Old Red Sandstone with a shingled spire. The tower and the nave are of the thirteenth century whilst the chancel was rebuilt in the fourteenth. The spire was added in the early eighteenth century and the whole was restored by John Prichard and John Pollard Seddon in 1856–7.
Either side of the East window of the chapel are two stone corbels which are said to represent Edward II. The interior also has a number of seventeenth and eighteenth century funerary monuments of high quality and stained glass by Charles Eamer Kempe.
References:The Gravensteen is a castle in Ghent originating from the Middle Ages. The name means 'castle of the counts' in Dutch. Arnulf I (918–965), Count of Flanders, was the first to fortify this place, building a medieval bastion on this high sand dune, naturally protected by the river Leie and its marshy banks. This bastion consisted of a central wooden building and several surrounding buildings, also in wood.
In the early 11th century, the wooden building was replaced by a stone residence, consisting of three large halls that made up three storeys, connected by a stone stairwell. The monumental stone staircase, the light openings, the fireplaces built into the walls and the latrines were signs of considerable luxury and comfort in those days. There was probably also a tower.