Pope Pius XI, born Ambrogio Damiano Achille Ratti (; 31 May 1857 – 10 February 1939), reigned 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."