Wikipedia
Carbery, or the Barony of Carbery, was once the largest barony in Ireland, and essentially a small, semi-independent kingdom on the southwestern coast of Munster, in what is now County Cork, from its founding in the 1230s by Donal Gott MacCarthy to its gradual decline in the late 16th and early 17th centuries. His descendants, the MacCarthy Reagh dynasty, were its ruling family. The kingdom officially ended in 1606 when Donal of the Pipes, 13th Prince of Carbery chose to surrender his territories to the Crown of England; but his descendants maintained their position in Carbery until the Cromwellian confiscations, following their participation in the Irish Rebellion of 1641.
Its modern descendants in name are the baronies of Carbery West and Carbery East, but Carbery once included territories from several of the surrounding baronies as well. To the north/northwest it shared a long and shifting border with the Kingdom of Desmond ruled by the rival MacCarthy Mor dynasty, and to the east/northeast an also shifting border with the vast Earldom of Desmond.
However, despite its small size in comparison to its neighbors, Carbery was one of the very wealthiest principalities in Ireland. This wealth came not, for the most part, from its predominantly rocky lands, but from its numerous excellent harbours, and greatest proximity to France and Spain. Some of the eastern portion of the principality was however quite fertile. The MacCarthys Reagh were reported to have the greatest income of all the Gaelic princes in Ireland. Only the Earls of Desmond, who were intermittently able to force the MacCarthys to pay them tribute in order to avoid continual harassment, were wealthier.
Carbery is fortunate to be very well documented for a medieval Irish principality, the sources being diverse and fairly copious.
In 1621, an Earldom of Carbery was created for John Vaughan, 1st Earl of Carbery, and this became extinct in 1713 with the death of John Vaughan, 3rd Earl of Carbery. Two years later, the barony was granted to the Anglo-Irish politician George Evans, whose descendants still hold the title of Baron Carbery.