The close study of manor centres in Ireland is in its infancy. The archaeology of Castlemore, Co. Carlow, presents an opportunity to consider the medieval manor of Forth in detail. An earthen motte and its ruined bailey survive several hundred meters from a denuded graveyard. The intervening space is under constant cultivation. Field-walking and geophysical survey has revealed a previously unrecorded Deserted Medieval Village. House platforms and out-buildings are located within a series of closely-spaced property boundaries, and some 2,000 artefacts reveal the local pottery used on the site over several centuries. It is in effect a ‘street village’, which is major type of medieval nucleated settlement characterized by a linear street with properties extending away at right angles. A corpus of manorial and borough accounts survive for the manor of Forth. In an Irish context, the corpus represents a rich collection. An almost continuous run of annual accounts survive between 1279/80 and 1289/90. As Forth became a manor of the Bigod, earls of Norfolk during the thirteenth century, this study presents the opportunity to consider a secular manor in Ireland within the wider context of an international estate prior to the Black Death.