On Oct. 14, 1964, Nikita Khrushchev was removed as both premier of the Soviet Union and head of its Communist Party, History.com reports. He had been in power for 10 years.

Party leaders voted him out at a Central Committee meeting on Wednesday, Oct. 14, United Press International reported at the time. The official Soviet news agency, Tass, announced the next day that he had been "released" from his jobs, UPI said. History.com says he left office on Oct. 15.

Leonid Brezhnev was chosen as first secretary of the Communist Party, both outlets reported. That post held the real power in the Soviet Union, UPI said. Alexei Kosygin was named premier, UPI reported.

Khrushchev was 70 years old, UPI said. He had led the party since taking over from Josef Stalin and had been premier since March 27, 1958.

UPI reported that Khrushchev had been in trouble with some party members over several issues. These included his policy of peaceful coexistence with the West, repeated failures of Soviet farming and a split with China's Communist Party. His backdown in the Cuban missile crisis may also have hurt him at home, UPI said.

According to reports cited by UPI, the motion to retire him was made by the party's chief ideologist, Mikhail Suslov. Sources told UPI that party leaders felt he was growing too old to hold power.

The news took Washington by surprise, UPI reported. Stock prices in New York fell sharply around noon on the first unconfirmed reports of the shake-up.

The change came in the middle of the Vietnam War. History.com says the new Soviet leaders increased military aid to North Vietnam without pushing it to negotiate an end to the fighting.

What we know: Khrushchev was removed in October 1964, and Brezhnev took over the party.
What we don't: The full private debate among party leaders that led to his removal.