By Bob Reinalda · Version 14 October 2025
Was born 29 July 1905 in Jönköping, Sweden and died 18 September 1961 near Ndola, Northern Rhodesia (now Zambia). He was the son of Knut Hjalmar Leonard Hammarskjöld, lawyer and politician, and Agnes Almqvist.
Hammarskjöld, the youngest of four brothers, lived with his parents in Vasa castle in Uppsala until he was twenty-five. His father, who came from a family committed to public service without political affiliation, held several government positions (county governor, Prime Minister 1914-1917) and was an arbitrator in the Permanent Court of Arbitration. Hammarskjöld’s oldest brother Åke, Swedish diplomat seconded to the League of Nations, became the Permanent Court of International Justice’s Registrar in 1922. Hammarskjöld had a warm relationship with his mother. Her social assignments concerned children, poverty relief, the local community and handicrafts, culture and religion. She dealt intensively with theology and shared religious feelings with her son. After secondary school Hammarskjöld entered Uppsala University, where he, a lover of literature, first studied French literature and history (Bachelor of Arts, 1925), then three years of economics (including half a year in Cambridge in 1927, attending John Maynard Keynes’ lectures) and another two years of law (Bachelor of Laws, 1930). He moved to Stockholm, entering both government service as assistant secretary of a commission studying unemployment (1930-1934) and Stockholm University for his doctorate in political economy. The Stockholm School of Economics anticipated Keynesian politics and allowed him to use data from the commission’s study. In 1933 Hammarskjöld defended his dissertation on the spread of the business cycle, being publicly questioned by the economist Gunnar Myrdal, and became assistant professor (for three years).
In 1934 Hammarskjöld also became Second Under-Secretary at the Ministry of Finance, working toward a new approach to economic planning. Yet, in early 1935 Ivar Rooth, Governor of Sweden’s Central Bank (Riksbank), hired Hammarskjöld because he needed another economist on his staff. Rooth sent Hammarskjöld to the Bank for International Settlements in Basel, Switzerland and had him study the variety of central banks, also offering him a permanent position. However, in early 1936 Hammarskjöld became Under-Secretary in the Ministry of Finance, a position he kept until 1945. Soon he was successful in the required national budget reform by contributing key organizing concepts and winning ‘people over personally’ during the reform process (Lipsey 2013: 47). In 1941 the government made him Chairman of the Central Bank’s Board of Governors, thus becoming the first Swede to combine the two positions. He held the Chairman position until 1948, where he advocated for a planned economy. On a commercial mission to England in 1943 he learned that the Allied states distrusted Sweden’s position of neutrality, due to its trade with Nazi Germany. He followed the plans discussed at Bretton Woods closely (though Sweden had no observers there) but recommended that Sweden should wait and see to keep its freedom of manoeuvre. When Hammarskjöld discussed Sweden’s financial and trade problems with the Americans in 1947, he declared that Sweden’s absence ‘should not be given a principal meaning’ (Ahlström and Carlson 2006: 18).
As Sweden tried to remain neutral in the rising East-West tensions, it took time to join the United Nations (UN) (November 1946), the General Agreement on Tariffs and Trade (April 1950) and, in August 1951, the International Bank for Reconstruction and Development and the International Monetary Fund (with Rooth as the organization’s new Managing Director). From 1946 Hammarskjöld was also Envoy Extraordinary and Financial Advisor to the Ministry of Foreign Affairs, attending the 1947 Paris conference which launched the Marshall Plan and the meetings of the 1948 Organization for European Economic Cooperation, serving as vice-chairman of its Executive Committee (1948-1949). He also was a delegate to the Council of Europe (1949) and the UN General Assembly (in 1949; in 1951 as vice-chairman of the Swedish delegation; in 1952 as chairman). His focus shifted from the economy to foreign affairs when he took on positions as Under-Secretary in the Ministry of Foreign Affairs (1949-1951) and Minister without portfolio (1951-1953). In 1952 he diplomatically handled the Catalina incident, where two Swedish planes were shot down by the Soviet Union in international airspace over the Baltic Sea.
Due to an ongoing East-West rejection of candidates for the office of UN Secretary-General, following Trygve Lie’s resignation in November 1952, no acceptable successor was found. Yet, ten out of twelve Security Council members (none against, one abstention) selected the hardly known Hammarskjöld from a shortlist of four names on 31 March 1953. The choice surprised everyone, including Hammarskjöld, who the great powers considered a non-political bureaucratic civil servant. Even Lie, who had carved out a space for an active UN Secretary-General, feared that Hammarskjöld would be no more than a clerk. On 7 April the General Assembly approved Hammarskjöld with 57 of 59 votes. Catapulted into this position, Hammarskjöld started to restore the Secretariat (some 4,000 staff) by elaborating the position of the UN Secretary-General and the standing of the international civil service, using both his administrative experience and ethical ideas. His thoughts on action were based in the Swedish tradition of an impartial civil service and strongly influenced by an ethical perspective, as expressed in his spiritual diary Markings (1964, published after his death). His ethics were rooted in his interpretation of medieval mystics with ideas about service and solidarity of mankind, which he discussed with philosophers Martin Buber and Albert Schweitzer. He expressed his vision on UN action at press conferences, which he introduced as a regular form of exchange with representatives of the media, and in statements and speeches, both inside and outside the UN. He believed that leadership by the Secretary-General was the intention of the UN’s founders, as expressed in Charter principles in several articles, and defended his independence vis-à-vis other UN organs (Security Council, General Assembly, Trusteeship Council). Hammarskjöld frequently referred to the Charter and considered the UN a moral force. His reorganization improved the Secretariat’s set-up and efficiency. He made the Executive Office, headed by American Andrew Cordier, the centre for all work on political matters. Cordier made Hammarskjöld, fluent in multiple languages, personally greet all staff in New York (3,500), which increased their motivation. Hammarskjöld needed few hours of sleep and found time for his literary and artistic interests. He engaged museums and artists to contribute art to the UN headquarters and instituted the tradition of annual concerts on UN Day (24 October). Swedish Per Lind became his daily personal assistant and American Ralph Bunche, experienced in armistice agreements and awarded the 1950 Nobel Peace Prize, his assistant and troubleshooter in political work and peacekeeping.
When the People’s Republic of China (not a UN member, unlike the Republic of China or Taiwan) announced in November 1954 that it held detained United States (US) airmen who had served in the UN Command in Korea, US President Dwight Eisenhower called on the UN. Hammarskjöld felt he had to visit Peking himself and made sure that the General Assembly resolution included language that gave him considerable personal latitude as Secretary-General. Resolution 906(IX) of 10 December 1954 authorized him to undertake the mission ‘by the means most appropriate in his judgement’. He exchanged cables with Prime Minister Zhou Enlai, who received him in Peking in his individual capacity as Secretary-General, working toward the relaxation of international tensions and matters of concern to the Chinese. Even if it took months before all airmen were released, providing his good offices in this way became known as the ‘Peking Formula’ and the great powers realized that Hammarskjöld was someone to reckon with. 1955 was the year of the UN’s tenth anniversary, sixteen new member states and the conference on the peaceful uses of atomic energy.
In early 1956 Hammarskjöld made long trips to the Middle East and the Asia-Pacific to strengthen relations between the UN and its member states. Egypt’s nationalization of the Suez Canal Company in July, related to a US refusal to finance the construction of a dam on the Nile, resulted in a secretly prepared military response by France, Israel and the United Kingdom in late October (while the Soviet Union intervened militarily in Hungary to suppress a popular uprising). With the Security Council paralyzed, the Suez issue was transferred to an emergency session of the General Assembly, which called on the Secretary-General to act as appropriate. Initially sceptical about Canadian Prime Minister Lester Pearson’s proposal of a UN Emergency Force (UNEF) to move in and police a ceasefire, Hammarskjöld changed his mind. Bunche and Urquhart, the only Secretariat member with first-hand military experience, helped organize the group of military personnel, headed by E.L.M. Burns of the UN Truce Supervision Organization (founded to observe and maintain the 1948 Middle East ceasefire). Hammarskjöld proved central in all intense diplomatic discussions and in commanding UNEF. He convinced Egypt that its support of General Assembly Resolution 998(ES-1) to create UNEF implied acceptance of its presence on Egypt’s territory. In mid-November 1956 he flew with the first UNEF troops to Egypt and later explained the mission to all soldiers (some 3,500). They were not there to fight but to serve peace and order under UN authority. Since no UN helmets were available, US army helmets were painted blue. The UN also organized the canal clearance process. The Suez operation entrenched Hammarskjöld’s freedom of action (‘Leave it to Dag’), based on his moral authority in the sense of ‘devotion’ to UN principles (Fröhlich 2008: 161). UNEF (terminated by Egypt in 1967) proved the first of many UN peacekeeping operations, based on consent of the parties, impartiality and use of force limited to self-defence.
On 26 September 1957 Hammarskjöld was unanimously re-appointed as UN Secretary-General. Believing that unanimity was politically required for his second term, he felt more independent in his position as Secretary-General. In the 1958 conflict in the Middle East between Lebanon and its neighbours, he refused an armed peacekeeping force and instead created a UN observation group in Lebanon, which helped to defuse the conflict. He enriched the diplomatic vocabulary with the term ‘UN presence’, having Pier Spinelli, head of the UN Geneva Office, act as the first of many ‘personal and special representatives of the Secretary-General’ (Lipsey 2013: 358). In the winter of 1958-1959 Hammarskjöld visited major countries in South Asia as well as Moscow, where he met with Nikita Khrushchev, given ongoing East-West tensions and distrust between the Soviet Union and the US over nuclear testing and military flights over the Arctic. Hammarskjöld had little influence on issues on the agenda such as Laos, the Palestinian refugees and the expulsion of the Dalai Lama from Tibet.
In early 1960 Hammarskjöld visited 24 African countries and noticed that the number of capable leaders was limited. Later that year twelve new African states were admitted to UN membership. Soviet-US relations deteriorated after a US spy plane was shot down over Soviet territory in May. Civil strife was threatened in newly independent Congo, with the Soviet Union supporting one side and the US the other. The return of Belgian troops shortly after independence made the Congolese government appeal for UN assistance. Security Council Resolution 143(S/4387) of 14 July 1960 called upon Belgium to withdraw its troops and authorized the Secretary-General to provide the Congolese government with such military assistance as may be necessary until national security forces could take over. This resulted in a peacekeeping force with substantial military capacity (already 3,500 troops on 20 July). In September Khrushchev came to the UN General Assembly to berate the West. He accused Hammarskjöld of being pro-Western and demanded his resignation. He proposed to replace the Secretary-General by three secretaries (soon called ‘troika’): one from the West, one from the East and one from a neutral state. The General Assembly, however, rejected his proposal and Hammarskjöld refused to resign. The Congolese situation worsened because of the secession of Katanga by Moïse Tshombe, Prime Minister Patrick Lumumba’s accusation that the UN sided with Tshombe, and Lumumba’s assassination in January 1961. Hammarskjöld asked the Security Council to strengthen his mandate. In March the Soviet Union blamed Hammarskjöld for Lumumba’s death and again submitted its troika proposal, but once more without success as the US and the Asian and African members continued to back the Secretary-General. In May Hammarskjöld explained his vision about the restrictions of a Secretary-General in difficult situations in his lecture about the role of the international civil servant in law and in fact at Oxford University. On 18 September he and his staff, in route to negotiate a ceasefire in Congo, were killed in a plane crash in Northern Rhodesia.
This extremely tragic incident also presented the problem of choosing a successor as Secretary-General. The US wanted someone appointed quickly, but the Soviet Union created an impasse by again presenting its troika proposal. On 2 November the Security Council found the solution when Burmese diplomat U Thant agreed to complete Hammarskjöld’s term in office as Acting Secretary-General. The General Assembly approved the next day. The library at New York headquarters was named after Hammarskjöld and he was awarded the Nobel Peace Prize posthumously, having been nominated before his death, for ‘developing the UN into an effective and constructive international organization, capable of giving life to the principles and aims expressed in the UN Charter’ (Nobel Peace Prize 1961).
The first Rhodesian investigations into what happened before and during the crash of Hammarskjöld’s plane explained it as an accident. The 1962 UN’s inquiry, however, did not exclude sabotage or attack in the air. A 1992 Swedish report accused the Rhodesian officials on the ground of having deliberately delayed the search and rescue operations but dismissed allegations that the plane was shot down when approaching Ndola. Susan Williams, who raised the question of Who Killed Hammarskjöld? (2011), revealed more information suggesting that the crash probably was not simply an accident. She also noted the unavailability of information and disappearance of documents. Subsequent investigations supported the interference theory, rather than the accident one. The October 2024 report by former Tanzanian Chief Justice Mohamed Othman, in 2018 appointed as Eminent Person in the UN Hammarskjöld investigation, provided significant information in areas such as probable intercepts by member states of relevant information, the capacity of Katanga, or others, to have conducted a possible attack on Hammarskjöld’s plane and the presence of foreign paramilitary and intelligence personnel in the Ndola area. Othman is ‘almost certain that specific, crucial and to date undisclosed information exists in the archives of Member States’ of the UN (https://press.un.org/en/2024/sgsm22413.doc.htm).
(all websites accessed 15 August 2025)
Bob Reinalda, 'Hammarskjöld, Dag Hjalmar Agne Carl' in IO BIO, Biographical Dictionary of Secretaries-General of International Organizations , edited by Bob Reinalda, Kent J. Kille and Jaci L. Eisenberg. https://sandbox.zenodo.org/records/506830 (sandbox preview)
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