Water-power as a factor of industrial location in early medieval Ireland: The environment of the early Irish water mill

It has long been known that certain water-powered mill sites, owing to the suitability of their water supply, have continued in use since the later medieval period. But when, exactly, did medieval millwrights begin to make empirical observations on the efficacy of a particular source of hydro-power and, indeed, on the very site of the mill itself? In the present paper, important new archaeological evidence from early medieval Ireland (c. AD 600-1100), is used to demonstrate that conscious decisions on the location of mills employing various types of freshwater and estuarine supplies were already being made by the early decades of the 7th century AD. Furthermore, not only were increasingly more challenging locations being adapted for use by early medieval Irish millwrights, but the availability of water-power had already become an important factor in the choice of site for larger monasteries.