High security surrounded the courthouse in a suburb of the port city of Piraeus. Golden Dawn opponents have called rallies for Monday to protest against racism and right-wing extremism.

The 69 defendants include 17 former and present members of parliament, some of whom face up to 20 years in prison.

Former party leader and founder Nikos Michaloliakos and other prominent defendants were not present in the dock of the specially built courtroom inside the high-security prison.

The crackdown on Golden Dawn began when one of its supporters stabbed to death musician and left-wing activist Pavlos Fyssas in September 2013. The suspected perpetrators identified themselves as members of the party, whereupon police raided party offices and arrested party spokesman Ilias Kassidiaris, party leader Nikos Michaloliakos, and six members of parliament, including hardline MP Christos Pappas on charges such as gun possession.

Kasidiaris, who sports a swastikalike tattoo on his arm, gained notoriety in the run-up to national elections in 2012, when he repeatedly slapped a female lawmaker from the Communist Party during a political debate that was broadcast live on TV.

A number of defendants, including Kassidiaris and Michaloliakos, were released from the high-security prison pending trial. They have claimed the legal proceedings are no more than a political witch hunt.

Political party with neo-Nazi agenda

Golden Dawn has a neo-Nazi agenda, with an emblem resembling the Nazi swastika; its members express admiration for Adolf Hitler. The party is notorious for attacking immigrants and leftist politicians, capitalizing on fears of immigration and economic frustration.

It registered as a political party in 1993, promoting the idea of a "Greater Greece," expanding the country's territory into southern Albania, the Republic of Macedonia and southern Bulgaria.

Ten years later it had begun campaigning on an anti-European and anti-Muslim agenda. In national elections in 2012 the party won 7 percent of the vote – and over 20 percent in some of the Athens neighborhoods with large immigrant communities – winning 21 seats in the Athens parliament.

In the latest general election, in January this year, Golden Dawn became Greece's third largest political party, still holding 17 seats in parliament.

The trial is expected to last several months.

rg/jil (AFP, dpa)