The son of an American-born mother and the grandson of a founder of the London publishing house of Macmillan & Co., he was educated at Balliol College, Oxford. He distinguished himself in combat during World War I and entered politics after the war. He sat in the House of Commons from 1924 to 1929 and from 1931 to 1964. When Winston Churchill formed his World War II coalition government (May 1940), Macmillan, who had bitterly condemned British "appeasement" of Nazi Germany in the late 1930s, was appointed parliamentary secretary to the Ministry of Supply. After 10 months as colonial under secretary, he was sent (Dec. 30, 1942) to northwest Africa as British minister resident at Allied Forces Headquarters, Mediterranean Command. There his efforts to secure good relations with Dwight D. Eisenhower, Charles de Gaulle, and other high Allied officers improved his skills as a politician.
At the end of the war in Europe, Macmillan was secretary of state for air in Churchill's "caretaker" government (May-July 1945). After the Conservatives regained power in 1951, he was successively appointed minister of housing and local government (October 1951) and minister of defense (October 1954) by Churchill and then served as foreign secretary (April-December 1955) and chancellor of the exchequer (1955-57) under Sir Anthony Eden. He was appointed prime minister on Jan. 10, 1957, following the resignation of Eden in the wake of the Suez crisis, and was elected leader of the Conservative Party 12 days later.
Macmillan immediately had to deal with a national shortage of money, and his chancellor of the exchequer, Peter Thorneycroft, resigned (January 1958) in protest against government spending. Macmillan worked to improve British-U.S. relations, which had been strained by the Suez crisis, and his old partnership with General, now President, Eisenhower was helpful in this regard. Macmillan himself supervised the conduct of foreign policy as prime minister. He had several conferences with presidents Dwight D. Eisenhower and John F. Kennedy, and he visited Nikita S. Khrushchev in Moscow (February 1959). At home, Macmillan gave firm support to Britain's array of postwar social programs. He led the Conservative Party to a resounding victory in the 1959 general election by effectively contrasting Britain's prewar unemployment with its postwar full employment under the slogan "You've never had it so good."
The Nassau agreement (December 1962) between Macmillan and Kennedy, that the United States should furnish nuclear missiles for British submarines, enraged Charles de Gaulle, who then was head of the French state and who insisted on a Europe uncontrolled by the United States. The subsequent French veto (Jan. 29, 1963) of Great Britain's entry into the European Economic Community was a severe blow to Macmillan. For most of his term Macmillan had been held in high esteem by his party. But Britain's adverse balance of payments led the government to impose a wage freeze and other deflationary measures from 1961 on, and this caused Macmillan's government to lose popularity. Another setback was an apparent Soviet espionage attempt involving John Profumo, the secretary of state for war, which ended in the latter's resignation (June 1963). Macmillan's reputation was partly rehabilitated by the successful negotiations (July 1963) among Great Britain, the United States, and the Soviet Union for the Nuclear Test-Ban Treaty, but demands continued within his own party for a new and younger leader, and, after undergoing surgery, he resigned his office on Oct. 18, 1963.
Macmillan refused a peerage and retired from the House of Commons in September 1964. He then began producing his memoirs: Winds of Change, 1914-1939 (1966); The Blast of War, 1939-1945 (1967); Tides of Fortune, 1945-1955 (1969); Riding the Storm, 1956-1959 (1971); Pointing the Way, 1959-1961 (1972); At the End of the Day, 1961-63 (1973); and The Past Masters: Politics and Politicians, 1906-1939 (1975). He later accepted a peerage and was created an earl in 1984.
Macmillan's papers are currently held at the Bodelian Library at Oxford University and his Foreign Office papers are held by the Public Record Office. Most of Macmillan's correspondence is held at repositories around the country, although his letters to Desmond Donnelly can be found at the National Library of Wales.