Pope Pius XI (; , 31 May 1857–10 February 1939), born Achille Ratti, was an Italian priest of the Roman Catholic Church and the 260th Pope from 1922 to 1939.
Priest
Ratti was ordained as a priest in 1875.
Father Ratti was a professor at the Padua Seminary from 1882 to 1888. He worked at Ambrosian Library of Milan from 1888 to 1911; and at the Vatican Library from 1911-1914.
Bishop
In 1919, Pope Benedict XV made Ratti a Bishop of Lepanto.
In 1921, Benedict named him Archbishop of Milan.
Cardinal
In 1921, Ratti was made a cardinal.
Pope
Cardinal Ratti was elected pope on February 6, 1922; and he chose the name Pope Pius XI.
Some of his decisions were controversial. He made 18 concordats (treaties) with foreign governments. They included the Lateran Concordat with Italy in 1929; and the Reichskoncordat with Germany in 1933.