Mr Spedding, 50, becomes the second chief of the Secret Intelligence Service - known in Whitehall as 'C' - to be announced officially. He will take over from Sir Colin McColl in September.
Mr Spedding, who has had a classic intelligence career devoted largely to the Middle East, was exposed early in his career as an MI6 officer working in Beirut by Philby in a interview the Soviet double agent gave to an Estonian journal.
Philby named a number of SIS officers in a move masterminded by the KGB in retaliation for the expulsion of 105 Soviet diplomats, journalists and trade officials in 1971. Since Philby had himself defected a decade earlier from Beirut, the names were probably fed to him by KGB counter-intelligence experts. It is unlikely he could have simply guessed after being shown a copy of the Diplomatic List, which showed Mr Spedding as the Second Secretary at the British Embassy to the Lebanon.
Despite having lost his cover, and the increasing personal risk caused by his exposure, Mr Spedding, a fluent Arabic, French and Spanish speaker who is one of the SIS's four operational directors, held a series of other Middle East posts including Abu Dhabi - after which he was awarded the OBE - and Amman, Jordan. He was moved in 1972 for two years to Santiago, Chile, where his posting coincided with the overthrow of Salvador Allende's Marxist government and his replacement by General Pinochet.
Mr Spedding went to the same school, Sherbourne, as Sir Colin's predecessor, Sir Christopher Curwen, and the spy novelist John Le Carre. A graduate of Hertford College, Oxford, he lists walking and medieval history among his recreations.
He is a member of Huntercombe Golf Club in Oxfordshire, to which Ian Fleming, the creator of James Bond, also belonged. Tom Hutchinson, the club secretary, said: 'There's nothing James Bondish about Mr Spedding. He's a perfectly ordinary, average looking man. There's nothing distinctive about him at all - that's probably the secret of his success. Everyone knew he was in the diplomatic service, but no one had any idea of his position or work.'
Of his golf skills he commented: 'He's a very enthusiastic golfer who only plays occasionally. He plays off a handicap of 20, which is very, very, run of the mill. I think he sees the club as a place to take fresh air, rather than somewhere to play competitive sport.'
Mr Spedding takes over at a time when the service is dealing with allegations that a recently arrested Russian arms industry official had been spying for Britain. The official Russian news agency, Tass, claimed that the man had been supplied with invisible writing materials and means of secretly supplying information to intelligence agents at the British Embassy in Moscow.
But he also comes to MI6, whose budget is a surprisingly modest pounds 150m a year, at a time of rapid change. Sir Colin stayed on for two years after his 60th birthday to provide continuity after the end of the Cold War, the decision to avow the service publicly and the Bill passing through the Commons which will subject both MI6 and MI5 to a measure of parliamentary scrutiny.
Unlike when Stella Rimington was appointed head of MI5, the Foreign Office issued no photographs yesterday of Mr Spedding. Nor did he give a news conference.
At an unprecedented news conference last November Sir Colin - declining to be photographed - explained that 'secrecy is our absolute stock in trade'.
He added: 'People come to work for us, risk their lives for us sometimes, risk their jobs often, because they believe that SIS is a secret service.'
Mr Spedding, who is married with two sons aged 19 and 23, will earn pounds 82,925 as the equivalent of a second permanent secretary.Reuse content