The Irish name of the town () originally referred to a MacCarthy dynasty castle which once stood in the area. This should not be confused with Dunboy Castle – two miles west of the town – which was the seat of the O'Sullivan Beare family. Donal Cam O'Sullivan Beare, together with other Gaelic lords and with Spanish aid, rebelled against the English Crown. During the Siege of Dunboy the castle was reduced by the forces of Elizabeth I in 1602. He then retreated with his followers to Leitrim. O'Sullivan Beare's stance was commemorated in 2002, and there is a plaque in Irish and English on the castle ruins commemorating those who died.