Although at the time of writing, we have found no direct archaeological evidence for a medieval mill, there was certainly a mill at Clodock before the existing post-medieval structure. When it was built is as yet unknown.

Arguably, Clodock is the best mill site in the upper Monnow catchment area, with a plentiful, fast flowing and stable water supply. North of Clodock the Monnow has not yet been joined by its tributaries, the Escley Brook and the Olchon, so the water supply for the mills higher than Clodock is less reliable. Below Clodock, the land is flatter and more liable to flooding and the Monnow begins to meander, which endangers weirs. It is therefore likely that Clodock was one of the first mill sites to be developed.

The settlement of Clodock has a long pedigree. The earliest parts of Clodock church are Norman, but the original church was founded in the 6th century. According to the Book of Llandaff, the oxen drawing the bier of the murdered King Clydog refused to ford the River Monnow, so he was buried on the spot and a church built over his grave. By the 8th century, Clodock was the centre of a large estate including much of the present-day parish, which may well have supported a mill.

The Domesday Book is normally invaluable for identifying early watermills. It refers to some 6000 watermills in England, including over 100 in Herefordshire. However, in AD1086 Clodock was still part of the Welsh kingdom of Ewyas and was therefore not covered by the Domesday survey.

The first firm evidence we have for a mill at Clodock is an inquisition of 1327, which states that Theobald de Verdun held at Ewyas Lacy, along with the castle and various other assets, a moiety of three mills . A moiety is a half share, so we can infer from this that the mills already existed before the death of Walter de Lacy in 1241, when the lordship was divided between his two granddaughters, Margaret and Matilda.

A bailiff's account for 1493 names the mills. “Concerning the issues of Seynt Cladok and the mill called Castelmyll, nothing because they are ruinous for want of repair. But he answers as to 10 shillings from the corn-mill of Michelchurch thus demised to Richard Seicell this year”.

By 1532 all three mills “lie wholly in ruins for want of repair” and remained so for the rest of the century.

The manorial accounts for 1594 -1600 for the lordship of Ewyas Lacy again refer to three mills. “Of any profits ifsuing from a moiety of the Mills called Castle Mill Uske Mill otherwise Michell Churche and Cradok Mill had this year as in divers years preceeding - nothing - because for many years past they have been thrown down and are totally in ruins”.

It is remarkable that for the whole of the 15th century the three mills in the lordship of Ewyas Lacy all lay in ruins. For most of this period, one moiety of the lordship was merged with the Crown estates, while the other moiety was held by the Nevill family. Was Ewyas Lacy just too inconvenient and unimportant for any one to concern themselves with the state of the mills?

At some time in the 17th century Clodock Mill was rebuilt. It would have been nothing like the mill we see today. It would have been a simple, single-cell structure with two storeys and probably an attic, similar to the medieval mill it replaced. The wooden undershot waterwheel would have powered a single pair of millstones. Over the next 350 years extensions were added. First some living quarters, then a stable and cart shed. As demand for the services of the mill increased, a cross-wing was added so that it could run two pairs of stones. In the 19th century the house was extended and a dairy and pig styes were added.

The mill ran until 1954, but country corn mills were by then no longer economically viable. When we came to Clodock in 2001 the water wheel was in a state of collapse and millrace was badly silted up. Conservation and restoration work were carried out and on 13th May 2011 the mill started grinding corn once again.