Cardinal, born at Piscina, Abruzzi; having been sent by the Pope one of an embassy to France, he gained the favour of Richelieu, who recommended him to Louis XIII. as his successor, and whose successor, being naturalised as a Frenchman, he became in 1642, an office which he retained under the queen-regent on Louis' death; he brought the Thirty Years' War to an end by the peace of Westphalia, crushed the revolt of the Fronde, and imposed on Spain the treaty of the Pyrenees; at first a popular minister, he began to lose favour when cabals were formed against him, and he was dismissed, but he contrived to allay the storm, regained his power, and held it till his death; he died immensely rich, and bequeathed his library, which was a large one, to the College Mazarin (1602-1661).