A Co Donegal man has appeared at the Old Bailey in London, charged with the murder of four British soldiers in the 1982 Hyde Park IRA bomb blast.
John Downey, 61, was arrested at Gatwick Airport on Sunday.
He is accused of being responsible for a car bomb left in South Carriage Drive, which killed the soldiers as they rode through the park to the Changing of the Guard.
The explosion injured other members of the Household Cavalry and killed seven horses as they travelled from their barracks to Buckingham Palace.
Mr Downey was charged with murdering Roy Bright, Dennis Daly, Simon Tipper and Geoffrey Young, and with intending to cause an explosion likely to endanger life.
The accused appeared on videolink from Belmarsh prison.
He was remanded to a preliminary hearing before Mr Justice Sweeney at the court on 5 June. No application for bail was made.