Achille Ratti was born May 31, 1857, near Milan, the son of a silk factory manager. He entered the seminary at the age of ten where his scholastic abilities were soon recognized. Ratti eventually earned doctorates in theology, canon law and philosophy at the Gregorian University in Rome, but his real interest was in history. He was ordained in 1879, became a professor at the seminary in Padua for eight years and then worked at the Ambrosian Library in Milan, eventually becoming its prefect. In 1912, Pius X made him assistant librarian at the Vatican Library and prefect in 1914. He wrote and published many historical articles and was also an avid mountaineer scaling, amongst others, Mont Blanc and the Matterhorn.
In 1918, Pope Benedict XV recognized not only his flair for languages and scholastic prowess, but also his diplomatic potential. He sent him first as an Apostolic Visitor to Poland and in 1919, consecrated him archbishop and nuncio of Lepanto. He was sixty years of age and on his first pastoral assignment, one which he is credited with handling skillfully. When the Bolsheviks threatened to attack Warsaw in 1920, he refused to leave, thus showing great courage as well. In 1920, the government of Warsaw expelled him when he became the target of unfounded Polish national resentment. Benedict XV then made him archbishop of Milan and raised him to the cardinalate. In Milan he was known for his energetic and innovative style.
In February 1922, just months after his elevation to the cardinalate, Benedict XV died of pneumonia. In a conclave lasting four days with fourteen ballots, the choice centered on the continued need for a pontiff with diplomatic skill. The choice was between Cardinal Merry del Val and Cardinal Gasparri. Achille Ratti was a compromise between the conservative and progressive factions of the conclave. Ratti was sixty-four years of age, took the name Pius XI and would rule for seventeen years. His first gesture was to impart his urbi et orbi blessing from the external balcony of St. Peter’s Basilica, a sign of his willingness to negotiate a peaceful solution to the Roman Question with the Italian government.