The fourth son of Hjalmar Hammarskjold, Prime Minister of Sweden during the years of World War-I was brought up in the university town of Uppsala where his father resided as Governor of the county of Uppland.
After Trygve Lie's resignation from the post of UN Secretary General in 1953, the Security Council decided to recommend Hammarskjöld's name.
He was selected on March 31 with the majority of 10 out of eleven states. The UN General Assembly elected him in the April 7-10 session, by 57 votes out of 60.
Hammarskjöld started his term by establishing his own secretariat of 4,000 administrators and setting up regulations that defined their responsibilities.
He insisted that the Secretary-General should be able to take emergency action without the prior approval of the Security Council or the General Assembly.
During his tenure, Hammarskjöld tried to better relations between Israel and the Arab states.
In 1955 he went to mainland China to negotiate the release of 15 US pilots who had served in the Korean War and been captured by the Chinese.
In 1956 he established the United Nations Emergency Force (UNEF) and the very nest year also took note of the Suez Crisis.
From December 18, 1959 to January 31, 1960, the Secretary-General visited 21 countries and territories in Africa.
On the insistence of the former Belgian colony and now independent Congo, the Secretary-General asked the Council to act "with utmost speed" on sending military troops to the region.
Hence, the United Nations Force in the Congo was established and Hammarskjöld himself made four trips to the Congo in connection with the United Nations operations there.
His fourth and the final trip to the Congo began on September 12, 1960 and terminated with the fatal plane accident.