U Thant was a Burmese diplomat and served as the third Secretary-General of the United Nations, from 1961 to 1971. He was chosen for the post when his predecessor, Dag Hammarskjöld, died in September 1961. One of his most noteworthy accomplishments during his tenure as Secretary General was his valuable assistance in facilitating the negotiations between U.S. President John F. Kennedy and Soviet premier Nikita Khrushchev during the Cuban Missile Crisis, thereby narrowly averting the possibility of a major global catastrophe.
"U" is an honorific in Burmese, roughly equal to "Mr". "Thant" was his only name. In Burmese he was known as Pantanaw U Thant, in reference to his home town of Pantanaw.