AA man has appeared in court charged with the murder of four British soldiers in the 1982 Hyde Park IRA bomb blast.
John Downey, 61, of County Donegal, was arrested at Gatwick Airport in May.
He spoke only to confirm his name at a preliminary hearing at the Old Bailey.
Downey 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 Royal Household Cavalry and killed seven horses as they travelled from their barracks to Buckingham Palace.
Downey is charged with murdering Roy Bright, Dennis Daly, Simon Tipper and Geoffrey Young, and with intending to cause an explosion likely to endanger life.
Judge Mr Justice Sweeney continued his conditional bail.