Built around 1181 by Hugh de Lacy, one of the most powerful Anglo-Norman lords in Ireland, this fortification was likely a motte-and-bailey castle; a type of early medieval stronghold consisting of a raised earthwork mound topped with a wooden or stone keep. De Lacy, who served as Lord of Meath and later Justiciar of Ireland, constructed numerous such castles across the country as he expanded Norman control into Leinster and beyond.

Today, visitors to Tullowphelim will find no visible remains of this once-important fortress. The site has been completely absorbed back into the landscape, leaving only historical records and archaeological surveys to tell its story. The castle’s existence was documented in the Archaeological Inventory of County Carlow, published by the Stationery Office in 1993, though scholars like Bradley noted as early as 1989 that no physical traces remained above ground.

The disappearance of Tullowphelim Castle is not unusual for Norman fortifications of this period. Many early motte-and-bailey castles were abandoned as the Normans consolidated their power and built more permanent stone structures elsewhere, or were destroyed during the frequent conflicts that characterised medieval Ireland. While the castle itself has vanished, its brief existence represents a crucial moment in Irish history, when the Anglo-Normans were rapidly transforming the political and physical landscape of the island through their network of fortifications.