The Orsini feud with the Colonna took a papal bull to stop
For centuries two Roman clans, the Orsini and the Colonna, fought for control of the city, until a papal bull ordered a halt in 1511. Sixty years later the heads of both houses sealed the peace by marrying nieces of the same pope. The Orsini alone had produced five popes and 34 cardinals.
The family liked to claim descent from the Julio-Claudian emperors, tracing itself to one Ursus, probably a 9th-century count of Tivoli. Its real ascent began with Giacinto Bobone, who became Pope Celestine III in 1191. Among the first great nepotist popes, he made two nephews cardinals and let a cousin buy a cluster of fiefs, including Vicovaro and Nettuno, that became the core of Orsini territorial power.
Matteo Rosso the Great was effectively lord of Rome from 1241, after beating imperial troops, until 1243. He drove the Colonna out of the city, pushed Orsini lands south to Avellino and north to Pitigliano, and kept the family firmly Guelph. His roughly ten sons split the estates into branches named for their strongholds, Bracciano, Monterotondo and Pitigliano among them, and one son became Pope Nicholas III, who promptly raised relatives to high office.
Over the following centuries Orsini men served as senators of Rome, royal officials in Naples and condottieri who switched between France and Spain in the Italian Wars. Marriages bound them to the great dynasties: Clarice Orsini married Lorenzo de' Medici, and other daughters wed into the Farnese. Politics could be lethal. After Orsini leaders were linked to a failed plot against Cesare Borgia in 1502, Cardinal Giovanni Battista Orsini was assassinated the next February, and two kinsmen were strangled.
The Bracciano line, anchored by a castle built in 1426, was the most powerful in Lazio. Paolo Giordano became its first duke in 1560, a capable soldier who nonetheless arranged the murder of his wife, Isabella de' Medici, and had to flee north. His descendants moved to Rome, sank into debt, and in the late 17th century the last duke, Flavio, sold Bracciano to Livio Odescalchi. Maiolica jars and stands painted with the Orsini arms, made around 1460 to 1510, survive at the Metropolitan Museum.
Source: Orsini family
