Istvan Dudas, then a colonel in the border guard, and three colleagues, were accused of crimes against humanity.

The appearance of Istvan Dudas,75, in court was greeted with howls of anger in the courtroom, with shouts of "murder" and "shame on you" by former participants in the revolution.

Opening the case, the prosecution said that the unit of border guards opened fire on about a 1,000 peaceful demonstrators in Mosonmagyarovar on 26 October 1956 with machine guns before throwing hand grenades.

The names of 55 dead and 78 injured were read out in court but others are believed to have been quietly buried by relatives.

According to his lawyer, Mr Dudas will plead not guilty to the charges and will argue that he ordered his men to stop shooting, not to start.

Campaign

The trial, the first related to events in 1956, came after a campaign by a small group of survivors.

In June the country's supreme court ruled that while murder was protected by a 15-year statute of limitations, crimes against humanity must be answered regardless of when they are alleged to have taken place.

Six further cases of troops opening fire on demonstrators are expected to follow.

Revolution crushed

The Hungarian revolution took place against a backdrop of power struggles in the Eastern bloc following the death of Stalin in 1953.

In 1953 the new Hungarian prime minsiter Imre Nagy pledged reforms but was deposed in 1955. Within a year the country became increasingly unstable as ordinary Hungarians became more and more prepared to challenge communism.

On 23 October 1956 students marched on Budapest with a list of demands but the peaceful demonstration descended into chaos when police opened fire, leading to pitched battles on the streets.

Rather than crushing the movement, the decision prompted elements of the army to join with the students and appeal to the West for aid. Within days, Mr Nagy returned to power at the head of a coalition government as Soviet forces stood back.

Within a week, the Nagy government sought United Nations recognition as a neutral state but the Soviet Union moved against it when the prime minister announced the country's withdrawal from the Warsaw Pact.

Amid bloody battles between students and Soviet forces, Mr Nagy was kidnapped while he sought to negotiate a deal. He was later executed after a secret trial.