Despite their displacement, the MacCarthys retained their ability to rule. For almost five centuries, they dominated much of Munster, with four distinct branches: those led by the MacCarthy Mor ("Great MacCarthy"), nominal head of all the MacCarthys, who ruled over much of south Kerry; the Duhallow MacCarthys, who controlled north-west Cork; MacCarthy Riabhach ("grey") based in Carbery in south-west Cork; and MacCarthy Muskerry, on the Cork/Kerry border. Each of these families continued resistance to Norman and English encroachment up to the seventeenth century when, like virtually all the Gaelic aristocracy, they lost almost everything.
After the great scattering of the Gaelic aristocracy at the end of the seventeenth century the MacCarthys, like so many other, became prominent in the armies of the Catholic kings of Europe. Justin MacCarthy (d. 1694), the first Duc de Clancarthy was the founder of the Irish Brigade in the army of Louis XlV of France. The last in the line Pol MacCarthy was the 7th Duc and fought in the army of Napoleon lll.
Eugene McCarthy was U.S. senator for Minnesota from 1958 to 1970, and a one-time Democratic party candidate for the Presidency. His less salubrious namesake Senator Joseph McCarthy (1909-1957) made his reputation through a ferocious anti-Communist witch-hunt and left McCarthyism in the political lexicon.