The House of Colonna, also known as Sciarrillo or Sciarra, is an Italian noble family, forming part of the papal nobility. It was powerful in medieval and Renaissance Rome, supplying one pope (Martin V) and many other church and political leaders. The family is notable for its bitter feud with the Orsini family over influence in Rome, until it was stopped by papal bull in 1511. In 1571, the heads 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 family is 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, in the Alban Hills. Further back, they trace their lineage past the Counts of Tusculum via Lombard and Italo-Roman nobles, merchants, and clergy through the Early Middle Ages — ultimately claiming origins from the Julio-Claudian dynasty and the gens Julia whose origin is lost in the mists of time but which entered the annals for the first time in 489 BC with the consulship of Gaius Julius Iulus.
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 a 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 false information from the beginning of the 16th century.
Giovanni Colonna (born c. 1206) nephew of Cardinal Giovanni Colonna di Carbognano, made his solemn vows as a Dominican around 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.