Pope Pius IX
Born as Giovanni Maria Mastai Ferretti, Pope Pius IX was the ninth child born into the noble family of Girolamo dai Conti Ferretti (1750–1833) and Caterina Antonia Maddalena Solazzei di Fano (1764–1842).
Pope Pius IX had been the first future pope ever to have been in America. Upon his return to Rome, the successor of Pius VII, Pope Leo XII, appointed him head of the hospital of San Michele in Rome (1825–1827) and canon of Santa Maria in Via Lata. Pope Leo XII appointed the 35-year-old Mastai Ferretti Archbishop of Spoleto in 1827.
He was head of the Catholic Church from 1846 to 1878, the longest verified papal reign. He was notable for convoking the First Vatican Council in 1868 and for permanently losing control of the Papal States in 1870 to the Kingdom of Italy. Thereafter, he refused to leave Vatican City, declaring himself a “prisoner of the Vatican”
He centralized power in the church in the Holy See and Roman Curia, while also clearly defining the Pope’s doctrinal authority. His chief legacy is the dogma of papal infallibility. Pope John Paul II beatified him in 2000.
Sources:
https://www.franciscanmedia.org/saint-of-the-day/saint-adrian-of-canterbury/