Ivan Serov

State Security General Ivan Alexandrovich Serov (Russian: Ивáн Алексáндрович Серóв, 13 August 1905 – 1 July 1990) was a prominent leader of Soviet security and intelligence agencies, head of the KGB between March 1954 and December 1958, as well as head of the GRU between 1958 and 1963. He was Deputy Commissar of the NKVD under Lavrentiy Beria, and was to play a major role in the political intrigues after Joseph Stalin's death. Serov helped establish a variety of secret police forces in Central and Eastern Europe after the rise of the Iron Curtain, and played an important role in crushing the Hungarian Revolution of 1956.

Serov headed both the political intelligence agency (KGB) and the military intelligence agency (GRU), making him unique in Soviet/Russian history.

Serov played a key role in the Hungarian crisis, sending reports to the Kremlin from Budapest, and escorting visiting Soviet Presidium leaders Anastas Mikoyan and Mikhail Suslov via an armoured personnel carrier into Budapest on 24 October, because there was too much shooting in the streets.[12]

In 1956, the Hungarian revolution overthrew the incumbent Communist Hungarian government and in response to this, János Kadar formed a new government more loyal to Moscow, but this received little popular support. Serov was responsible for arresting supporters of Imre Nagy who were trying to negotiate with Soviet military officials.

Serov organized deportations of Hungarians, among them Imre Nagy. Serov co-ordinated the abduction of Pál Maléter, the Hungarian general, and the disruption of peace talks between the Red Army and the Hungarian forces.

More information on the Wikipedia page.