Orsini, an Italian family, conspicuous in the middle ages. Their ancestors were distinguished at Rome as early as the first half of the 12th century. Giordano, for his services to the pope as a soldier, was made a cardinal in 1145, and in 1152, in the capacity of legate, was sent to Conrad III. of Germany; while his nephew, Matteo, held the post of prefect of Rome. Toward the end of the 12th century Orso ruled the city as its senator, while another member of the family, Celestine III., was pope. Another Matteo, styled the Great, was elected senator, at the same time holding large fiefs in the Campagna. One of Matteo'8 sons, Giovanni, became pope under the name of Nicholas III. in 1277, and endeavored to perpetuate the dignity of senator in his family, for whom he secured princely alliances. The Orsinis now reached the zenith of their fortune, and their quarrels with the Colonnas filled the annals of Rome. They were Guelphs, and generally found on the side of the popes, while their rivals adhered to the Ghibelline party. The castle of Bracci-ano, on the lake of that name, was the chief residence of the family, who possessed besides many strongholds in Rome and its vicinity.

The Orsini, with the Colonna and Savelli families, were the special objects of the enmity of Pope Alexander VI. - The Neapolitan branch of the family is still extant, Some of its early members became counts of Nola and dukes of Gravina in the 15th century. Pietro Francesco gave up his duchy to his brother Dome-nico, entered the church, and in 1724 became pope under the name of Benedict XIII. The family still hold the highest rank among Italian nobles. Prince Domenico Orsini, duke of Gravina, born Nov. 23, 1790, died in Rome, April 18, 1874. He was a lieutenant general, and bore the honorary appellations of assistant prince of the holy see and senator of Rome. He married, Feb. 6, 1823, Maria Luisa, daughter of the celebrated banker Torlonia, duke of Bracciano, who bore him three daughters and one son, Filippo, present duke of Roccagorsa. The seat of the family is still at Rome, but their usual residence until the revolution of 18G0 was at Naples in the Gravina palace.