The corn mill and associated kiln recorded at Kilbillaghan in County Westmeath appear on the Ordnance Survey six-inch map of 1837, but the deeper question is whether they sit on the footprint of something far older, a working mill that was already significant enough in the early seventeenth century to be written into crown patent rolls.

The documentary trail begins in 1612, when Robert Dillon of Cannorstown received a royal grant covering the settlement of Kilbellaghan, an area that at the time included a castle, twenty houses, twelve gardens, a mill, and a plowland. A plowland was a unit of landholding loosely tied to the area one plough could work in a season, and its presence alongside the mill suggests a functioning agricultural community of some scale. By 1619 the picture had shifted: Edmond Malone and Teige O'Higgan surrendered to the Crown a stone castle, twenty messuages (dwellings with their adjoining land), and a water-mill in the same townland. That same year, a separate royal confirmation of a grant to Edmond Malone of Kilgarvan included yet again a watermill and associated lands in Kilbellaghan. The mill, in other words, appears three times in the patent rolls within a single decade, passed between grantees as part of a larger package of castle, houses, and farmland. Whether the 1837 Ordnance Survey mill occupies the precise spot of that earlier structure has never been established; the location of the medieval mill within the townland remains unidentified.