The castle has a strong defense structure with features like a thickened-end wall and barzitans (projecting turrets) upon the tower house in order to keep its inhabitants secure.
The castle was constructed by an Irish clan known as O’Donoghue Mór in the 15th century. In the Second Desmond Rebellion in the early 1580s, the McCarthy Mor clan took ownership of the fortress.
After the Irish Confederate Wars ended, the Brownes were able to retrieve their lands by proving their heir was far too young to have participated in the revolt. By around 1688, they had constructed a luxurious abode close to the castle.
Unfortunately, their loyalty to King James II of England following the Glorious Revolution resulted in their exile. The castle was then turned into military barracks, remaining so until the beginning of the 1800s. The Browne family did not come back to reside at Ross Castle, rather opting to construct Kenmare House close to Killarney.