
Gladwyn Jebb (on the right) attending the first session of the United Nations General Assembly in London on the 10th of January 1946. Jebb was the Acting Secretary-General from October 1945 to the appointment of Trygve Lie in 1946. Photo by Marcel Bolomey / UN Photo

Lie served as the Secretary-General from 1946 until his resignation from his second term in 1952. Photo by UN Photo

Hammarskjöld (in the middle right) served as the Secretary-General from 1953 until his death in a plane crash in 1961.
Photo by SAS Scandinavian Airlines

U Thant was appointed as the Acting Secretary General in 1961 after Hammarskjöld´s death. In 1962 he was elected as the permanent Secretary-General serving until 1971. Photo by Nijs Jack de. / Anefo / Nationaal Archief

Kurt Waldheim attending meetings of the Security Council in Panama City in 1973. Waldheim served as the Secretary-General from 1972 to 1981. Photo by Yutaka Nagata / UN Photo

Perez de Cuellar served as the Secretary-General from 1982 to 1991.
Photo by Bogaerts Rob / Anefo / Nationaal Archief

Boutros-Ghali holding a live video conference at UN Headquarters in 1995. He served as the Secretary-General from 1992 to 1996.
Photo by Milton Grant / UN Photo

Kofi Annan preparing for an interview at ITU TV Studio in 2013. He served as the Secretary-General from 1997 to 2006. Photo by Claudio Montesano Casillas / ITU

Ki-moon in Kinshasa in 2013. Ki-moon served as the Secretary-General from 2007 to 2016. Photo by Dominic Chavez / World Bank

António Guterres, appointed as the Secretary-General in 2017, at the 40th anniversary of the VIC in 2019. Photo by Dean Calma / IAEA