life when he was sent to the monastery of the Friars Minor in Velletri, where he was put under the care of his maternal uncle Fra Leonardo Patrasso. He was granted a canonry at the cathedral in the family's stronghold of Anagni, with the permission of Pope Alexander IV. The earliest record of him is as a witness to an act of Bishop Pandulf of Anagni on 16 October 1250. In 1252, when his paternal uncle Pietro Caetani became Bishop of Todi, in Umbria, Benedetto followed him to Todi and began his legal studies there. His uncle Pietro granted him a canonry in the Cathedral of Todi in 1260. He also came into possession of the small nearby castello of Sismano, a place with twenty-one fires (hearths, families). In later years Father Vitalis, the Prior of S. Egidio de S. Gemino in Narni testified that he knew him and conversed with him in Todi and that Benedetto was in a school run by Rouchetus, a Doctor of Laws, from that city. Benedetto never forgot his roots in Todi, later describing the city as "the dwelling place of his early youth", the city which "nourished him while still of tender years", and as a place where he "held lasting memories". Later in life he repeatedly expressed his gratitude to Anagni, Todi, and his family. In 1264 Benedetto entered the Roman Curia, perhaps with the office of Advocatus. He served as secretary to Cardinal Simon de Brion, the future Pope Martin IV, on a mission to France. Cardinal Simon had been appointed by Pope Urban IV (Jacques Pantaléon), between 25 and 27 April 1264, to engage in negotiations with Charles of Anjou, Comte de Provence, over the Crown of Naples and Sicily. On 1 May 1264 he was given permission to appoint two or three tabelliones (secretaries) for his mission, one of whom was Benedetto. On 26 February 1265, only eleven days after his coronation, the new pope, Pope Clement IV wrote to Cardinal Simon, telling him to break off negotiations and travel immediately to Provence, where he would receive further instructions. On the same day, Clement wrote to Charles of Anjou, informing him that the pope had 35 conditions that Charles must agree to in accepting the crown; he also wrote to Henry III of England and his son Edmund that they had never been possessors of the Kingdom of Sicily.