The House of Altieri was an ancient noble family of Rome, present in the history of the city since the Middle Ages, yet now extinct. In addition to the title of Prince granted by the Pontiffs, branches of the Altieri were also part of the aristocracy of Genoa and of Venice. The family consolidated its position in the ranks of the great senatorial and cardinal aristocracy thanks to dynastic marriages with families like the Colonna, Paluzzi, Chigi, Odescalchi, Doria-Pamphili, Ruspoli, Barberini, Borghese and in more recent times the di Napoli Rampolla, relatives of the famous Cardinal Mariano Rampolla del Tindaro, Secretary of State of Pope Leo XIII, not to mention a multitude of princely families of Europe. Their fiefs consisted of the principality of Oriolo Romano and Vejano and the duchy of Monterano in the Alto Lazio. The Altieri were among the protagonists of the history of the city from the earlier Middle Ages until the second half of the twentieth century, reaching the apogee of their power with Emilio Bonaventura Altieri, elected pope in 1670 under the name of Clement X.

Pope Clement X, born Emilio Bonaventura Altieri, was head of the Catholic Church and ruler of the Papal States from 29 April 1670 to his death, in July 1676. Elected pope at age 79, he has since been ranked as the oldest pope at the time of his election.