The Colonna family was a powerful noble family in medieval and Renaissance Rome, supplying one Pope and many other leaders. Their family is notable for their bitter feud with the Orsini family over influence in Rome until it was stopped by Papal Bull in 1511; in 1571 the Chiefs of both families married the nieces of Pope Sixtus V.
According to tradition, the Colonna are a branch of the Counts of Tusculum — by Peter (1099-1151) son of Gregory III, called Peter "de Columpna" from his property, the Columna Castle, in Colonna, Alban Hills.
In 1297, Cardinal Jacopo disinherited his brothers Ottone, Matteo, and Landolfo of their lands. The latter three appealed to Pope Boniface VIII, who ordered Jacopo to return the land, and furthermore hand over the family's strongholds of Colonna, Palestrina, and other towns to the Papacy. Jacopo refused; in May, Boniface removed him from the College of Cardinals and excommunicated him and his followers for four generations. The Colonna family (aside from the three brothers allied with the Pope) declared that Boniface had been elected illegally after the unprecedented abdication of Pope Celestine V three years previously. The dispute lead to open warfare, and in September Boniface appointed Landolfo to the command of his army, to put down the revolt of Landolfo's own relatives. This he did, and by the end of 1298 Colonna, Palestrina, and other towns had been captured and razed to the ground. The family's lands were distributed among Landolfo and his loyal brothers; the rest of the family fled Italy.
In the 1300s, the family sponsored the decoration of the Church of San Giovanni, most notably the floor mosaics.
In 1728, the family added the name Barberini to its family name when Giulio Cesare Colonna di Sciarra married Cornelia Barberini, daughter of the last male Barberini to hold the name, Taddeo Barberini.
The Colonna family have been Prince Assistants to the Papal Throne since 1710, though their papal princely title only dates from 1854.
The family residence in Rome, the Palazzo Colonna, is open to the public.