Achille Ratti

Pope Pope Pius XI
Bishop of Rome
Pius XI in 1930
Papacy began	6 February 1922
Papacy ended	10 February 1939
Predecessor	Benedict XV
Successor	Pius XII
Orders
Ordination	20 December 1879 by Raffaele Monaco La Valletta
Consecration	28 October 1919 by Aleksander Kakowski
Created Cardinal	13 June 1921 by Benedict XV
Personal details
Birth name	Ambrogio Damiano Achille Ratti
Born	(1857-05-31)31 May 1857 Desio, Lombardy-Venetia, Austrian Empire
Died	10 February 1939(1939-02-10) (aged 81) Apostolic Palace, Vatican City
Previous post	Chief of the Ambrosian Library (1907–14) Vice-Prefect of the Vatican Library (1914–15) Prefect of the Vatican Library (1915–19) Titular Archbishop of Naupactus (1919–21) Apostolic Nuncio to Poland (1919–21) Titular Archbishop of Adana (1921) Archbishop of Milan (1921–22) Cardinal-Priest of Santi Silvestro e Martino ai Monti (1921–22)
Motto	Raptim Transit (It goes by swiftly Job 6:15) Pax Christi in Regno Christi (The Peace of Christ in the Realm of Christ)
Signature
Coat of arms

Papal styles of Pope Pius XI
Reference style	His Holiness
Spoken style	Your Holiness
Religious style	Holy Father
Posthumous style	None

Pope Pius XI, (Italian: Pio XI) born Ambrogio Damiano Achille Ratti (Italian pronunciation: [amˈbrɔ:dʒo daˈmja:no aˈkille ˈratti]; 31 May 1857 – 10 February 1939), reigned as Pope from 6 February 1922 to his death in 1939. He was the first sovereign of Vatican City from its creation as an independent state on 11 February 1929. He took as his papal motto, "Pax Christi in Regno Christi," translated "The Peace of Christ in the Kingdom of Christ."

Pius XI issued numerous encyclicals, including Quadragesimo anno on the 40th anniversary of Pope Leo XIII's groundbreaking social encyclical Rerum novarum, highlighting the capitalistic greed of international finance, the dangers of socialism/communism, and social justice issues, and Quas primas, establishing the feast of Christ the King in response to anti-clericalism. The encyclical Studiorum ducem, promulgated 29 June 1923, was written on the occasion of the 6th centenary of the canonization of Thomas Aquinas, whose thought is acclaimed as central to Catholic philosophy and theology. The encyclical also singles out the Pontifical University of Saint Thomas Aquinas, Angelicum as the preeminent institution for the teaching of Aquinas: "ante omnia Pontificium Collegium Angelicum, ubi Thomam tamquam domi suae habitare dixeris" (before all others the Pontifical Angelicum College, where Thomas can be said to dwell).