Built probably in the later 1500s, with an oak panel inside bearing the date 1591 and the initials ‘R.R. M.S.’ marking a marriage, the castle features many of its original defensive elements: a segmental arched doorway on the west side protected by a machicolation, a rebate for a yett (iron gate), crenellated parapets, and corner machicolations at the northeast and southeast angles. The main house measures approximately 17.8 metres north to south and 9 metres east to west, with a four-storey stair tower offset to the south and west, whilst an early 17th-century extension adds another 8.2 metres to the southern end.

The castle’s ownership tells a fascinating story of Irish landed families through the centuries. The manor of Tildavin, which evolved into Tomhaggard, was held by the Hore, Rede, and St. John families during the 13th and 14th centuries. The Rossiters, thought to be a branch of the Rathmacknee family, appear in records from the 17th century; William Rossiter owned what the Civil Survey of 1654-6 described as “a fair castle and windmill” along with 265 acres across various townlands. Following Cromwell’s conquest, William was marked for transplantation to Connaught in 1653, and the estate passed to William Ivory in 1667 before coming into the hands of the Harvey family.

The Harveys’ tenure at Bargy Castle proved particularly dramatic during the 1798 Rising, when owner Bagnel Harvey played such a prominent role in the rebellion that the Crown confiscated the estate; it was eventually returned to his brother James in 1816. The family retained ownership well into the 20th century, during which time they made substantial Victorian alterations, replacing the windows with pointed or elliptical headed ones that give the castle its current Gothic Revival touches. Above the original doorway, a heraldic plaque bears a broad cross surrounded by five carved heads, whilst chimney flues supported on corbels project from the east wall. Still occupied today, Bargy Castle remains a tangible link to centuries of Irish history, from medieval knights’ fees through plantation, rebellion, and restoration.