Cahir Castle, one of the largest castles in Ireland, was built in County Tipperary in 1142 by Conor O'Brien, Prince of Thomond, on an island in the river Suir. Now situated inside the town centre of Cahir, the castle is well preserved and has guided tour and audiovisual shows in multiple languages.
In 1375, the castle was granted to Butler, newly-created Baron of Cahir, for his loyalty to Edward III. The Butlers of Cahir sided with the Irish in the Elizabethan wars, and in 1599 the castle was captured after a three day siege by the army of the Earl of Essex.
In the Irish Confederate Wars of the late 1640s (waged during the English Civil War) the castle was besieged twice. In 1647 George Mathew, the guardian of the young Lord Cahir, surrendered to Lord Inchiquin following his victory at the battle of Knocknanauss. In 1650 he surrendered again to Oliver Cromwell, during his conquest of Ireland without a shot being fired.