MOSCOW - George Blake, who died Saturday in Moscow aged 98, was a British Cold War spy and Soviet double agent who spent half his life in Russia after dramatically escaping jail in London.

The last surviving member of a notorious generation of British defectors, Blake was seen as one of the West's most damaging traitors and claimed to have betrayed hundreds of agents to the KGB.

The bearded spy, however, trod a very different path to becoming a Soviet agent than that taken by the establishment insiders of the infamous Cambridge spy ring: Kim Philby, Donald Maclean and Anthony Burgess, all recruited while at the British city's prestigious university.

Born George Behar in the Netherlands in 1922 to a Dutch mother and Egyptian Jewish father, who was a British subject, he led a peripatetic youth that took him through Cairo and into the Dutch World War II resistance before joining Britain's MI6.

Conversion to communism

Blake -- a practicing Calvinist Protestant -- said he willingly offered to work for the KGB after witnessing the bombing of innocent civilians by U.S. forces during the Korean war, when he spent a harrowing period as a North Korean captive.

"I viewed communism as an attempt to create the kingdom of God in this world. The communists were trying to do by action what the church had tried to achieve by prayer," Blake told one interviewer.

"I came to the conclusion I was no longer fighting on the right side."

After returning to London from captivity, Blake's first major coup for his new handlers was the exposure of a secret tunnel to spy on Soviet communications in East Berlin.

At the same time as he was becoming enmeshed ever deeper in his perilous work, handing over troves of secret information to the Russians, he married a woman named Gillian, who knew nothing of his double life, and they went on to have three sons.

Soon he moved to Berlin where he claimed to have betrayed all of the "maybe 500, 600" agents operating for the British in Germany.

Later Blake repeatedly denied accusations that those he gave up were executed by the Soviet secret police.

"I said to them I will only give you this information if you can assure me these people will not be executed," he said.

Escape to the USSR

Eventually, however, the tide turned on the traitor and the net finally closed when information from a turncoat Polish intelligence officer unmasked Blake.

Summoned to London for questioning, he admitted that he was a Soviet agent and was sentenced at a closed trial in 1961 to an unprecedented 42 years in prison.

But just five years into his sentence in 1966, Blake clambered up a rope ladder and over the wall of London's high-security Wormwood Scrubs jail to freedom with the help of an Irish petty thief and two anti-nuclear campaigners whom he had met inside.

Smuggled by his co-conspirators to the border with East Germany, he walked across the Iron Curtain and turned his back on the West for the last time.

In Moscow, Blake was celebrated as a hero with a string of medals and the rank of colonel from the KGB, and a flat in the center of the Soviet capital.

He married a Russian woman Ida after his first wife divorced him and had one son with her. Eventually he was also reconciled with his British children.

Blake, however, came to realize that communism in Russia did not live up to his hopes and he watched the system -- and finally the Soviet Union -- disintegrate.

Disappointment

"One of the main things, which to me was a disappointment, was that I believed that a new man was born here," he told The Times newspaper.

"I realized very quickly that this was not so. They were just ordinary people like everyone else and that the same human passions, and greed and ambitions, which governed the lives of most people also governed their lives."

In 1990 he published his autobiography entitled "No Other Choice".

Blake lived out the final years in a wooden dacha on the edge of Moscow -- with his eyesight and hearing failing, he seemed a relic of another era.

While he kept his opinion of the rampant consumerism of modern Russia to himself, on his 90th birthday he was hailed by ex-KGB agent President Vladimir Putin as one of "a constellation of strong and courageous people, brilliant professionals."

In rare interviews, Blake insisted he had no regrets, despite the failure of the system that he dedicated his life to.

"I think it is never wrong to give your life to a noble ideal, and to a noble experiment, even if it doesn't succeed," he said.