Giacomo della Chiesa was born, 21 November 1854, to a noble family in Pegli, Italy. He studied law at the Royal University of Genoa and theology at Rome's Gregorian University. He was ordained to the priesthood in 1878, and earned a doctorate in sacred theology in 1879. Giacomo entered the papal diplomatic service in 1882, serving as secretary to the nuncio to Spain until 1887, and as secretary to the Vatican Secretary of State until 1901, when he was made undersecretary.
In 1907, he was ordained Archbishop of Bologna, and in May 1914 he was made a Cardinal, just three months before the death of Pius X and the beginning of World War I. He was elected to succeed Pius X, probably because of his diplomatic experience. As father to all Catholics, Benedict XV favored neither side in the war. But his policy of neutrality was misinterpreted by both sides, each regarding him as siding with the other. He pressed for a Christmas truce in 1914 to ward off the “suicide of Europe,” but was ignored. In 1917, he tried to broker a peace plan, but his efforts were unsuccessful. He was able, however, to arrange the exchange of disabled prisoners through neutral countries, and to have the sick and wounded sent to neutral countries for treatment and recuperation. Through his intercession, deported Belgians were allowed to return home, and he donated money to relieve those suffering the effects of the war throughout Europe. After the war, in 1919, he asked for a Vatican role in the Paris Peace Conference, but was turned down. He pleaded with the victorious Allies to lift the blockade against Germany, because of the suffering it caused to women and children, and he took up a Church-wide collection to buy food. For human solidarity, he favored the founding of the League of Nations, though the Vatican itself was excluded from membership.
Among his other actions as Pope, Benedict XV promulgated what was then the first unified Code of Canon Law in 1917, though he gave the credit to Pius X, his predecessor. He tried to improve relations with the anticlerical Republican government of France. And he emphasized the training of native priests in the mission territories of the Third World. He was friendly toward the Orthodox Churches, founding the Oriental Institute and the Congregation for Eastern Rites. He paved the way to two future pontificates, recognizing the abilities of Achille Ratti (Pius XI), whom he sent as his representative to Poland, and then promoted to Archbishop of Milan, and of Eugenio Pacelli (Pius XII), whom he put in charge of the prisoner-of-war work at the Vatican, and then sent as nuncio to Munich. In 1920 he canonized three Saints, Gabriel of the Sorrowful Mother, Joan of Arc, and Margaret Mary Alacoque.
Pope Benedict XV died of influenza, January 22, 1922. Among his last words were "We offer our life to God on behalf of the peace of the World.