He was born on 2 August 1881 in Biłka Szlachecka near Lviv as the son of Prince Jan Paweł Aleksander Sapieha and Seweryna Sapieha née Uruska; he was the husband of Teresa Lubomirska (from 1909). He attended secondary school in Lviv, later studied at the Polytechnic Institute in Zurich and finally graduated from the High School of Forestry. After his return to the country, he administered an estate in the Novogrudok Province. In 1916, he became the president of the Central Welfare Council and in the following year he tried to initiate a coup whose aim was the formation of an independent Polish government; in 1918, he made efforts to reach an understanding between the Regency Council and the Polish National Committee. After Poland had regained independence, he participated in the attempted coup against Jędrzej Moraczewski’s government on the night of 4–5 January 1919; after a short detention, he joined the army and was soon appointed the first Polish ambassador to London by Piłsudski (1919–1920); in the governments of Władysław Grabski and Wincenty Witos, he held the portfolio of the Minister of Foreign Affairs (June 1920–May 1921), accompanied Piłsudski on his journey to Paris in 1921 and signed the Polish-French political treaty. After tendering his resignation on 24 May 1921, he never returned to diplomacy. As member of conservative groups, he participated in organising the congress in Nesvizh (1926), which was to bring them closer to Marshal Józef Piłsudski, and in 1928–1930 he was a deputy to the Sejm from the Nonpartisan Bloc for Cooperation with the Government. During World War II, he found himself in the areas annexed by the USSR; in 1941, he managed to travel to London and did not return to the country after the war. He died on 20 February 1963 in Nairobi (Kenya).