Leading family of the Roman nobility in the 11th and 12th centuries, intimately and consistently associated with the papacy during the gregorian reform. Its earliest known representative was the Roman Jew Baruch, whom the sources call Benedictus Christianus after his conversion (date unknown). He married a lady of the Roman aristocracy and died before Nov. 19, 1051. His son Leo, an important figure by 1051, supported Hildebrand in every way. Last mentioned in 1062, he was succeeded by his son Petrus Leonis, who gave the family its name. Their closeness to Hildebrand, a notice in the Annales Pegavienses [Monumenta Germaniae Historica Scriptores 16:238], and other circumstantial evidence gave rise to the highly controversial theory that gregory vi and gregory vii were related to them. urban ii took refuge from the followers of the antipope clement iii on the Tiber island, which was controlled by Petrus Leonis, and he died in Petrus Leonis's fortified house near the church of S. Nicola in Carcere (close to the theater of Marcellus). Petrus Leonis remained a faithful supporter of Urban's successors paschal ii, gelasius ii, and callistus ii. He died between 1124 and 1130, perhaps in 1128.
His son Petrus (called, like his father, Petrus Leonis) was for a time a student in Paris and a monk at Cluny and was raised by Paschal II not later than 1113 to the rank of cardinal deacon and by Callistus II in 1120 to that of cardinal priest. The growing influence of the Pierleoni aroused the enmity of the other leading Roman family, the frangipani. More important, under honorius ii, new forces opposed to the older cardinals of the reform began to rise in the Sacred College under the leadership of the chancellor, Aimeric of Santa Maria Nuova. Upon Honorius's death (Feb. 14, 1130), a committee of six cardinals dominated by Aimeric elected the cardinal deacon Gregory of Sant'Angelo pope (innocent ii). Later in the day the majority of cardinals (21) elected to the papacy Cardinal Pierleoni, who called himself Anacletus II. He prevailed for a time in Rome and most of Italy, but Innocent, with the powerful help of bernard of clairvaux, was victorious. Upon the death of Anacletus in 1138 the schism came virtually to an end.
Anacletus's brothers remained prominent adherents of the papacy, except for Jordan, who in 1144 became the official leader of the rebellious populace of Rome after the restoration of the Roman Senate and received the title patricius. A nephew of Anacletus, Hugh was made bishop of Piacenza in 1154 and cardinal bishop of Tusculum in 1164 or 1165 (d. 1166). He was the uncle of another member of Alexander III's Sacred College, also named Hugh, cardinal deacon of Sant'Angelo (1173 to 1178), cardinal priest of San Clemente (1178 to 1182), and legate to England (1175 to 1176) and France (1176 to 1177).
Monuments of the family are found especially in Roman churches of the 16th and 17th centuries.
Bibliography: Main study still p. fedele, "Le famiglie di Anacleto II e di Gelasio II," Archivio della Società romana di storia patria 27 (1904), 399–440. r. l. poole, "Benedict IX and Gregory VI," Proceedings of the British Academy 8 (1917–18), 199–235, esp. 219–226. p. f. palumbo, Lo Scisma del MCXXX (Rome 1942), see index, 696. h. bloch, "The Schism of Anacletus II and the Glanfeuil Forgeries of Peter the Deacon of Monte Cassino," Traditio 8 (1952), 159–264, esp. 159–182, with references to the earlier literature. f. j. schmale, Studien zum Schisma des Jahres 1130 (Cologne 1961), esp. 15–28, 66–82, weak. h. wolter, Lexikon für Theologie und Kirche, ed. j. hofer and k. rahner, 10v. (2d, new ed. Frieburg 1957–65) 8:496–497. p. e. schramm, "Das Zeitalter Gregors VII," Göttingische gelehrte Anzeigen 207 (1953) 62–140, esp. 66–73, literature on the origin of Gregory VI and VII. v. forcella, Iscrizioni delle chiese e d'altri edificii di Roma, 14 v. in 7 (Rome 1869–84). v. spreti, Enciclopedia storiconobiliare italiana, 8 v. (Milan 1928–35), v. 5.