The great barns built by landowners of medieval England are among England's most important historic monuments. Impressive structurally and architecturally, they are not only beautiful but have much to tell us about the technology of the time. But, unlike homes, castles, and churches, barns were centers of production, where grain crops were stored and threshed, and they therefore offer a glimpse of a different side of medieval life--the ceaseless work of farming, on which the lives of both the rich and poor depended.

The Great Barn of 1425-7 at Harmondsworth, Middlesex explores one...