Original: Pope John XXIII , born Angelo Giuseppe Roncalli ( 25 November 1881 -- 3 June 1963 ) , known as Blessed John XXIII since his beatification , was elected as the 261st Pope of the Catholic Church and Sovereign of Vatican City on 28 October 1958 .
Simplified: The Blessed Pope John XXIII ( Latin : Ioannes XXIII ) , born Angelo Giuseppe Roncalli ( 25 November 1881-3 June 1963 ) , was the Pope of the Roman Catholic Church from 1958 until his death in 1963 .