The Colonna family is an Italian noble family; it was powerful in medieval and Renaissance Rome, supplying one Pope and many other Church and political 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 nieces of Pope Sixtus V. Thereafter, historians recorded that, "no peace had been concluded between the princes of Christendom, in which they had not been included by name". 
According to tradition, the Colonna are a branch of the Counts of Tusculum — by Peter (1099–1151) son of Gregory III, called Peter "de Columna" from his property, the Columna Castle, in Colonna, Alban Hills.
The first cardinal from the family was appointed in 1206 when Giovanni Colonna di Carbognano was made Cardinal Deacon of SS. Cosma e Damiano. For many years, cardinal Giovanni di San Paolo (elevated in 1193) was identified as member of the Colonna family and therefore its first representative in the College of Cardinals, but modern scholars have established that this was based on the false information from the beginning of 16th century.
Giovanni Colonna (1206 c.- ), nephew of Cardinal Giovanni Colonna di Carbognano, made his solemn vows as a Dominican c. 1228 and received his theological and philosophical training at the Roman studium of Santa Sabina, the forerunner of the Pontifical University of Saint Thomas Aquinas, Angelicum. He served as the Provincial of the Roman province of the Dominican Order and led the provincial chapter of 1248 at Anagni. Colonna was appointed as Archbishop of Messina in 1255.
At this time a rivalry began with the pro-papal Orsini family, leaders of the Guelph faction. This reinforced the pro-Emperor Ghibelline course that the Colonna family followed throughout the period of conflict between the Papacy and the Holy Roman Empire.
In 1297, Cardinal Jacopo (Giacomo Colonna) 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 following 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 Colonna 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.
Family enmity with Pope Boniface VIII led to destruction of the fortress at Palestrina and to the seizure of the Pope at Anagni by Sciarra Colonna in 1303. Sciarra, apparently, smacked the Pope publicly in his face. It was he who, in old age, crowned Louis IV of Bavaria as Holy Roman Emperor in 1328. In honor of this event, the Colonna family was granted the privilege of using the imperial pointed crown on top of their coat of arms.
The family remained at the centre of civic and religious life throughout the late Middle Ages. In 1248, after having dedicated her entire life to serving God and the poor, Margherita Colonna died. A member of the Franciscan Order, she was beatified by Pope Pius IX in 1848.
14th century to 18th century
In the 14th century, the family sponsored the decoration of the Church of San Giovanni, most notably the floor mosaics. In 1314, Cardinal Egidio Colonna died at Avignon, now in France, where the Popes had withdrawn. An Augustinian, he had studied theology in Paris under St. Thomas of Aquinas to become one of the most authoritative thinkers of his time, and tutor to French king Philip IV the Fair, (1268 - 29 November 1314). The celebrated poet Petrarch, was a great friend of the family, in particular ofGiovanni Colonna and often lived in Rome as a guest of the family. He composed a number of sonnets for special occasions within the Colonna family, including "Colonna the Glorious, the great Latin name upon which all our hopes rest". In this period, the Colonna started claiming they were descendants of the Julio-Claudian dynasty (similar spurious claims are common among the old Roman nobility, the Massimo case probably being the best known).
Oddone Colonna (1369-20 February 1431) reigned as Pope Martin V from 14 November 1417 to 20 February 1431.
Vittoria Colonna became famous in the sixteenth century as a poet and a figure in literate circles.
In 1627 Anna Colonna, daughter of Filippo I Colonna, married Taddeo Barberini of the family Barberini; nephew of Pope Urban VIII.
In 1728, the Carbognano branch (Colonna di Sciarra) of the Colonna 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 and granddaughter of Maffeo Barberini (son of 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 every Saturday morning.
The main 'Colonna di Paliano' family is represented today by Prince Marcantonio Colonna di Paliano, Prince and Duke of Paliano (b. 1948), whose heir is Don Giovanni Andrea Colonna di Paliano (b. 1975), and by Don Prospero Colonna di Paliano, Prince of Avella (b. 1956), whose heir is Don Filippo Colonna di Paliano (b. 1995).
The 'Colonna di Stigliano' line is represented by Don Prospero Colonna di Stigliano, Prince of Stigliano (b. 1938), whose heir is his nephew Don Stefano Colonna di Stigliano (b. 1975).
- Blessed Margaret Colonna (d. 1284)
- Sciarrillo Colonna, who took part in the Outrage of Anagni against Pope Boniface VIII
- Stefano Colonna, an influential noble in Medieval Rome an Imperial vicar in the early 14th century.
- Oddone Colonna, who ended the Western Schism as Pope Martin V (elected in 1417).
- Guido Colonna di Paliano
- Giovanni Colonna (1295-1348), influential cardinal during the Avignon papacy.
- Francesco Colonna (1453? - 1517?) [La "Pugna d'amore in sogno" di Francesco Colonna Romano, 1996, Maurizio Calvesi], who was credited, along with the monkFrancesco Colonna, with the authorship of the Hypnerotomachia Poliphili by an acrostic in the text. Also believed to have written the story.
- Fabrizio Colonna, who was the father of Vittoria Colonna, and a general in the Holy League.
- Vittoria Colonna, (1490 - 1547), friend of Michelangelo. Married in 1507 Spanish-Italian Fernando d'Avalos, marquis of Pescara, deceased 1525, adopting on becoming a widow, Alfonso d'Avalos, also marquis del Vasto, a nephew of her former husband.
- Prospero Colonna, (1452 - 1523), who fought alongside his cousin Fabrizio Colonna.
- Pompeo Colonna, (1479 - 1532), cardinal. A nephew of Prospero Colonna, mentioned above. Viceroy of Naples from 1530 to 1532.
- Marcantonio I Colonna (1478 - 1522) condottiero of the 15th-16th century.
- Marcantonio II Colonna the Younger, (1535 - 1584). Duke of Tagliacozzo. Son of Ascanio Colonna and Juana de Aragón. He participated in the naval Battle of Lepantoagainst the Turks, 7 October 1571 and was Viceroy of Sicily in 1577-1584. Prince of Paliano.
- Pirro Colonna, 16th century captain under Charles V, Holy Roman Emperor
- Federico Colonna y Tomacelli, Prince of Butera, (1601 - 1641) Viceroy of Valencia, in Spain, 1640–1641, Viceroy of Catalonia, 1641. He was Great Constable of the kingdom of Naples (1639-1641) as had been his father Filippo I Colonna, (1578 – 11 April 1639).
- Marcantonio V Colonna, Prince of Paliano, (1606/1610-1659)
- Lorenzo Onofrio Colonna Viceroy of Aragon, 1678–1681, in Spain.
- Carlo Colonna (1665 - 1739), created cardinal by Clement XI in 1706.
- History of the popes; their church and state (Volume III) by Leopold von Ranke(Wellesley College Library, reprint; 2009)
- Werner Maleczek, Papst und Kardinalskolleg von 1191 bis 1216, Vienna 1984, p. 154-155
- Helene Tillmann, "Ricerche sull'origine dei membri del collegio cardinalizio nel XII secolo. II/2. Identificazione dei cardinali del secolo XII di provenienza Romana", Rivista di Storia della Chiesa in Italia, 1975, p. 401-402
- http://books.google.com/books?id=AIFCN2Smn9cC&pg=PA17#v=onepage&q&f=false Accessed 2-24-2013
- http://books.google.com/books?id=bM6wwPZorcAC&pg=PA267#v=onepage&q&f=false Accessed 2-25-2013
- Fra Giovanni Colonna By Antonio N. Di Stefano, 1995, 30-31,http://books.google.com/books?id=AIFCN2Smn9cC&pg=PA31#v=onepage&q&f=false Accessed 2-24-2013
- Worldroots - Barberini
- Article by Guy de Stair Sainty on Papal Court
- Theroff's Gotha, with references to current, legitimate members of the princely family