sentences:  The castle is thought to date from 1035 where the original fortress may have been built by the O'Mahony clan.Known to have been in the hands of the Norman family of de Courcey and possibly extended in the 13th century, Kilbrittain Castle was the principal seat of MacCarthy Reagh family, Princes of Carbery, from the early 15th century.The castle was extensively restored and enlarged by the Stawell family in the 18th and 19th centuries.