The Priory Church of St Mary is the parish church of Usk. Its origin was as the church of Usk Priory, a Benedictine nunnery founded by Richard de Clare, 2nd Earl of Pembroke in the twelfth century.
The site of the church shows no evidence of a pre-Conquest church, and the earliest religious building there may have been a Norman church associated with Usk Castle on the site of the present West nave. In the years before his death in 1176, Richard de Clare, 2nd Earl of Pembroke founded a Benedictine nunnery on the site. In the thirteenth century the North aisle was added as a place of worship for the people of the town, separated with a screen from the parts of the priory used exclusively by the nuns. In the fifteenth century, two two-storyed Perpendicular porches were added to the North and West aisles, the probable builder being Sir William Herbert, who was also building on a grand scale at nearby Raglan Castle.
After the Dissolution of the Monasteries in the late 1530s, the priory church became the parish church of the town. Extensive restoration and new building occurred in 1884 when Thomas Henry Wyatt created a sanctuary by roofing over the crossing space next to the tower and added a further bay to the nave. A further restoration was undertaken in 1899–1900, when G E Halliday inserted new windows and re-roofed the nave and aisle.
The gatehouse to the original Benedictine nunnery stands at the entrance to the churchyard.
References:The Broch of Clickimin is a large and well preserved, though somewhat restored broch near Lerwick. Originally built on an island in Clickimin Loch (now increased in size by silting and drainage), it was approached by a stone causeway. The water-level in the loch was reduced in 1874, leaving the broch high and dry. The broch is situated within a walled enclosure and, unusually for brochs, features a large 'blockhouse' between the opening in the enclosure and the broch itself. Another unusual feature is a stone slab featuring sculptured footprints, located in the causeway which approached the site. Situated across the loch is the Clickimin Leisure Centre.