In a church so battered and stretched by the elements it is exceedingly difficult to date the masonry, especially as so much of it has been replaced by necessity, so many of the dates given are not particularly set in stone (no pun intended). The church was built immediately below the site of an enormous landslide dating back to the end of the Quaternary Ice Age, and as such the ground beneath was far from consolidated. The result is a building turned contortionist, with an incredible south lean to the chancel and north lean to the tower, making for some wonderfully trippy views, but also some engineering nightmares. The Leaning Tower of Pisa has a cant of 3.97°, but the tower of Cwmyoy's church puts it to shame with its lean of 5.2°. Thankfully, as the more recent buildings around the church do not appear to be suffering in the same way, it is likely that the unquiet earth is finally at rest.

It is possible that an earlier building existed on the site, as it would have stood on the old pilgrims' route to St. David's, but nothing of this earlier structure is to be found. The present church is a simple structure consisting of nave, chancel, west tower, and south porch, and the origins of this building appear to date back to the late 12th century, with the round arched northwest window of the nave being the oldest remaining feature. It is probably the case that the original building was a single-cell structure consisting only of the present nave, or potentially a two-cell structure comprising a nave and an earlier chancel, with the present chancel and porch being added at a later date. Hugh de Lacy, lord of the manor in the late 12th century, gave the church to the monks of nearby Llanthony Priory soon after its construction, with the monks continuing to serve the church until the priory's dissolution in 1538.

As for later work, the southeast nave window certainly dates from the late 13th or early 14th century, with the chancel's windows being late 14th century. Remarkably, the nave roof is original 13th century, despite having been stretched and strained to within an inch of its life. Four tiebeams were added to ease the roof's load in the late 16th or early 17th century. The tower also appears to be some flavour of medieval, but it is unknown exactly when. The nave's central south window was probably added in the 16th century, with the remaining three nave windows being identical and Victorian, presumably dating from the 1887 restoration by J. J. Spencer. The window at the west of the lowest stage of the tower is also Victorian, and two of the belfry louvres appear to have been enlarged at some point.

As for Spencer's restoration, it seems to have been largely commendable and sensitive, with the pews, pulpit, and roof sarking being replaced, as well as the aforementioned windows being inserted. It is also possible that the outer arch of the porch was rebuilt and potentially even the chancel arch. I wouldn't have put it past the Victorians to do away with the entire building and demolish it before it simply collapsed, but thankfully they decided to go down the route of repair instead, adding a menagerie of buttresses including the large flying ones at the north and west of the tower. Further buttressing was added in the 1960s, with metal rods inserted into the walls in order to stabilise the building.

The information here has been taken variously from the Cadw listing and a Britain Express article.

There is nothing that can quite prepare you for the sensation of approaching Cwmyoy's famously higgledy-piggledy church. The approach is through some of the very best Welsh countryside, with the Black Mountains and Honddu River providing the most wonderful of scenic backdrops. The village is a small and steep cluster of buildings which complement the church nicely whilst letting the church remain distinct as the jewel in its crown. Surprisingly for such a rural location, there is a rather handy small carpark just to the north of the church.

Approaching the church from the north is the best way in which to do it, as the south approach is rather too steep to get a good view of the church until you are outside its door. The northern aspect is absolutely majestic, with the valley, hills, and churchyard trees all framing the building most romantically. One can get a sense of the incredible crookedness of the church upon first sighting it, and the building gives the impression of being seconds away from tumbling down the mountain, tower and all. Entering the church is to step into a distinctly dark and chilly place, but the most remarkable character dominates the entire space, with every view being an entirely new configuration of off-kilter angles joining each other at the most unlikely of places. 

Once inside there is actually fairly little by way of material items to inspect, but the building's various aspects are inexhaustible and the power of this ancient space invites reflective lingering.

At the time of the Reformation, images of saints and Christ in particular began to be condemned as idolatry, and Royal Commissioners and local zealots alike took it upon themselves to rid our churches of some of their most accomplished and beautiful art as a result. It goes without saying that crucifixes absolutely fell under this category and the vast majority met their grisly end via the reformer's hammer. As such, it is a precious rarity for a church to be able to boast an intact medieval crucifix, and Cwmyoy can do exactly that. Dating from the 13th century, Cwmyoy's example is a small, rather worn depiction of the crucified Christ, featuring an unusual piece of headgear consisting of a mitred cap with three crosses, sometimes found on Irish examples. It is possible that this headgear is derived from the Holy Roman Empire.

The cross was dug up at a nearby farm in 1861 after presumably having been buried in order to escape the bludgeoning hand of King Henry VIII's men, but it seems that they never actually bothered to come all the way out here to the church anyway. After its unearthing the cross was replaced in the church, but in 1967 disaster struck, when the cross was stolen. It remained missing for several years until eventually, just by chance, the Keeper of Sculpture at the British Museum happened across it in a London antique shop and recognised it for what it was. Thankfully, it was then returned to the church where it remains, hopefully eternally.

Before even entering the building, these remarkable plaster panels inside the porch will strike any visitor as something remarkable and rare. However, they are almost never mentioned in any history or guide to the church, being absent from the Cadw listing and both the Wikipedia and Britain Express articles. However, from what I can gather, these panels actually used to be part of a plaster ceiling which was removed by Spencer in 1887 in order to expose the 13th century roof beams and the panels affixed to the walls inside the porch.

As a consequence of their absence from any official source, I have absolutely no idea how old these panels are, though I would hazard a very cautious guess at 17th or 18th century. Most of them are only small roundels, but there is one larger square panel with a roundel at its centre, the rest of the panel being more ornamented. I suspect that this panel is actually mounted upside down, as the flowers grow towards the floor and the hearts appear to be the wrong way up. There is no doubt about the panels being most crude in their execution in the grand scheme of things, but they are absolutely delightful to behold and add to the mystery and atmosphere of this distinctly rural church.