Rathfarnham Castle, which dates from Elizabethan times, is probably the earliest example of what is termed a ‘fortified house’ built in Ireland. State papers attest to the presence of a fortification at Rathfarnham from soon after the Norman Invasion. This was apparently one of a chain of castles built to protect Dublin from attack by Irish clans based in Wicklow. In 1583, following the Desmond Rebellion, the lands of Rathfarnham, then part of the estate of Viscount Baltinglass, were confiscated by the Crown, and Baltinglass and his four brothers were convicted of high treason for their part in the rebellion.