In 1952, he retired to Venice, but six years later, at the age of 76, he was surprisingly elected to a higher office, from which he defended the rights of all human beings in his Pacem in Terris.  
He began his career as secretary to Radini Tedeschi, the bishop of Bergamo, but after serving as a chaplain in World War I he was appointed to diplomatic service in Bulgaria.  In 1952, he retired to Venice, but six years later, at the age of 76, he was surprisingly elected to a higher office, from which he defended the rights of all human beings in his Pacem in Terris.  FTP, identify this man, born Angelo Roncalli, whose Papacy saw the beginning of the Second Vatican Council.
He began his career as secretary to Radini Tedeschi, the bishop of Bergamo, but after serving as a chaplain in World War
John XXIII (accept Angelo Roncalli before it is mentioned)