The Colonnas were among the most prominent families in medieval Rome. Between 1278 and 1348 three members of the College of Cardinals came from within their ranks, thus giving them a preeminent position at the curia, the Papal court. The author shows how such a family cardinal could make use of the prebend market to provide his relatives, the members of his household (the so-called familiares) and the further clientèle of his family with sources of income from the Church. The study also extends to cover the 30 years up to the outbreak of the schism in 1378, showing how the Colonnas contrived to offset the loss of an intermediary between themselves and the curia.