Yuri Vladimirovich Andropov (/ænˈdroʊpɔːf, -pɒf/; Russian: Ю́рий Влади́мирович Андро́пов, tr. Yuriy Vladimirovich Andropov; IPA: [ˈjʉrʲɪj vlɐˈdʲimʲɪrəvʲɪtɕ ɐnˈdropəf]; 15 June [O.S. 2 June] 1914 – 9 February 1984) was a Soviet politician and the General Secretary of the Communist Party of the Soviet Union from 12 November 1982 until his death fifteen months later.
In 1954, he was appointed Soviet Ambassador to Hungary and held this position during the 1956 Hungarian Revolution. Andropov played a key role in crushing the Hungarian uprising. He convinced a reluctant Nikita Khrushchev that military intervention was necessary. The Hungarian leaders were arrested and Imre Nagy executed.
After these events, Andropov suffered from a "Hungarian complex", according to historian Christopher Andrew: "he had watched in horror from the windows of his embassy as officers of the hated Hungarian security service were strung up from lampposts. Andropov remained haunted for the rest of his life by the speed with which an apparently all-powerful Communist one-party state had begun to topple. When other Communist regimes later seemed at risk – in Prague in 1968, in Kabul in 1979, in Warsaw in 1981, he was convinced that, as in Budapest in 1956, only armed force could ensure their survival
A full biography on the Wikipedia page