One of the most violent episodes of the Cold War took place in 1956 in Hungary.
The country attempted to break away from the control of the Soviet Union.
The Soviets responded by sending troops and tanks to crush the Hungarian uprising.
Thousands died in the fighting and the repression that followed.
This week, for the first time, a former top Hungarian communist official was detained for his part in the crackdown.
His name is Bela Biszku, 90, who became the nation's interior minister after Soviet forces reinstated communist control.
Biszku is accused of ordering security forces to fire on demonstrators on two separate occasions, causing the deaths of 51 unarmed civilians.
He's charged with war crimes under a new law brought in last year, and is now under house arrest.
Veronika Gulyas, a reporter for the Dow Jones news service in Budapest, says the 1956 uprising is still a divisive issue in Hungary.
That's one reason, she says, why it's taken so long to bring a prosecution.
Biszku's story was brought to public notice by a documentary in 2010.