Born 'Georg Behar' in Rotterdam, Holland, Blake had all the advantages his wealthy family could provide, good schooling, a comfortable home and a bright future. After the German invasion of the Netherlands he served in the Dutch underground before escaping to Britain. Once in England he changed his name to Blake and joined the Royal Navy. Because of his language skills, he was accepted by SOE, which sent espionage agents to Nazi-occupied countries in Europe to work with underground fighters against the Germans. After the War he was accepted into the Foreign Office and eventually posted to the British Embassy in Seoul. During the Korean War he was captured by the advancing North Koreans in 1950. Blake was held for three years while the Communists painstakingly and successfully conducted brainwashing techniques on the prisoner. This was the turning point in Blakes life. Upon his release, he requested that the FO transfer him permanently to SIS (MI6) so he could fulfil his deepest ambition, to become a British Intelligence Officer. His excellent World War II service with SOE suggested high qualification for the job and SIS accepted Blake. This was quite unusual in that British Intelligence had strict rule that all officers of SIS had to have complete British parentage.
Security checking also either ignored or failed to discover that in his teen's Blake had been very close to his cousin Henri Curiel, who later helped establish the Egyptian Communist Party in 1943. Curiel was to be shot dead in his Paris home in May 1978 by members of the extreme right wing 'Delta' group, thought to have link's to SDECE, the French Intelligence Service. An hour later a news agency received a call saying "The KGB agent, Henri Curiel, a traitor to France, which adopted him, finally ceased activity today". This was one of a number of odd aspects of Blake's background that remained unexplained and that were to come back later to haunt those responsible for clearing him for top-secret work. Blake became a SIS field officer in 1953. From this time until he was exposed by a German double agent, he would serve the KGB with stubborn loyalty, identifying more than forty Western agents to the Soviets, most or all lost their lives. Posted to West Berlin in 1955, Blake exposed the existence of Operation GOLD (the Berlin Tunnel) in 1956. As soon as the KGB received Blake's report they began feeding false information through the system until eventually breaking into the tunnel and closing down the Western intelligence operation. Blake was to move back to London to work at SIS headquarters. He would regularly meet his Soviet controller, Rodin (alias Korovin) in the Netherlands, using the excuse that he was visiting his Dutch relatives. Eventually he was transferred to the Arabic Language School at Shemlan just outside of Beirut in the Lebanon. This establishment was known throughout the intelligence world as a 'training school for British spies'.
Blake would be finally compromised by German double agent Horst Eitner. SIS brought Blake back to London with the offer of a high paying desk job at their Headquarters. Blake flew back to have what he thought would be a routine interview, but was arrested at Heathrow airport. After many long hours of interrogation, admitted that he had been a triple agent and had fed the KGB everything he knew. Moreover, he admitted that he had embraced communism as early as 1953 and had planned to spy for the Soviet Union from then on. Blake's trial was held in secret and few details of its records are available to this day. He was found guilty and was given the maximum sentence of fourteen years for each of three main charges, forty-two years in all. He would serve less than six of those years. Sent to Wormwood Scrubs prison he appeared to be a model prisoner. However on the October 22, 1967, Blake escaped to Moscow, where he was eventually given a post with the KGB.