One of the men accused of trying to bomb a London Underground train on 21 July has been remanded in custody.
The bomb suspect was charged at Paddington Green police station
Hussain Osman, 27, is charged with offences including the attempted murder of Tube passengers at Shepherd's Bush and conspiracy to murder.
Mr Osman, who was extradited from Italy on Thursday, was remanded in custody by Belmarsh magistrates until 8 December.
Three other men face the same charges as Ethiopian-born Mr Osman and are also due at the Old Bailey on that date.
All four suspects are also charged with two explosives offences and conspiracy to murder.
A tight security operation surrounded Friday's hearing at Bow Street Magistrates' Court, which sat at the Belmarsh prison complex in south-east London.
Mr Osman, dressed in a pale blue-grey open-necked shirt, hardly spoke during the hearing.
Hussain Osman was taken from prison in Rome to Ciampino Airport
He confirmed his name, and had the charges read to him, but said he did not have a fixed address.
Mr Osman - also known as Hamdi Issac - was arrested by Italian police in Rome a week after the failed attacks.
He was flown back to the UK on Thursday, after losing his appeal against extradition.
Anti-terrorism officers arrested him after his flight landed at RAF Northolt, in Middlesex, and he was later formally charged at Paddington Green police station, central London.
The three other men accused of taking part in the attempt to bomb three Tube trains and a bus - Ibrahim Muktar Said, 27, Yassin Hassan Omar, 24, and Ramzi Mohamed, 23 - are currently being held at Belmarsh high-security prison.
A fifth man, Manfo Kwaku Asiedu, 32, is charged with conspiracy to murder and conspiracy to cause explosions, in relation to an unexploded device found two days after the bomb attempts.
Ten others have been charged with withholding information from police or helping suspects evade arrest.
The failed 21 July attacks took place two weeks to the day after four suicide bombers killed 52 passengers on the London transport network.