Pearson, Lester Bowles, 1897–1972, Canadian diplomat and political leader, b. Ontario prov. He served in the Canadian army in World War I. Pearson taught history at the Univ. of Toronto from 1924 to 1928 and then joined the Canadian diplomatic service. After serving (1928–35) as a first secretary in the department of external affairs, he was attached (1935–41) to the London office of the Canadian high commissioner; he later held (1941–44) various consular posts. He was Canada's senior adviser at the Dumbarton Oaks (1944) and San Francisco (1945) conferences that led to the establishment of the United Nations, and he headed Canada's UN delegation. As chairman of the UN political and security committee in 1947, he played a decisive role in mediating the Palestinian crisis. From 1948, when he entered Parliament as a Liberal, to 1957 Pearson was minister of external affairs and took a leading part in Commonwealth affairs and the formation of the North Atlantic Treaty Organization. Pearson, one of the most respected members of the UN General Assembly, received the 1957 Nobel Peace Prize for his work on behalf of the United Nations in resolving the 1956 Arab-Israeli war. In 1958 he became head of the Liberal party and leader of the opposition. He led his party to a gain of 46 seats in the 1962 elections and succeeded John G. Diefenbaker as prime minister in early 1963. He retired as prime minister in 1968. He also served (1951–58) as chancellor of Victoria Univ. in Toronto. Among his books are Democracy in World Politics (1955), Diplomacy in the Nuclear Age (1959), and Words and Occasions (1970).
See his memoirs (2 vol., 1972–73).