His father was a Spanish Jew resident in Egypt, who fought for the British and was decorated in the First World War. After the war he settled in the Netherlands, where he met Blake’s mother. Blake, born in 1922, grew up in his mother’s middle-class, Calvinist tradition.His father’s death left the family in difficulties, so the 13-year-old boy was sent to live with his paternal aunt in Cairo. His cousins, both boys a decade older, were Blake’s first introduction to left-wing ideas The younger, Henri Curiel, was already a Communist. “His views had a great influence on me,” Blake said in 1991, “but I resisted them because I was a very religious boy.

It was my intention to become a minister in the Dutch Reformed Church but later on in life things changed. Many of his views acted as a time bomb.” (Curiel later became an leading anti-colonial activist, and was assassinated in Paris in 1978.)Blake was visiting his family in the Hague when the outbreak of the Second World War stranded him. The following year he was with his grandmother in Rotterdam when the Germans invaded. Returning to the Hague, he discovered his mother and two sisters had been evacuated to England. A half-Jewish British subject, he acquired false papers and went underground.

He was in the Resistance for two years until he escaped to England.On arrival he joined the Royal Navy, and was soon seconded to intelligence on account of his fluent Dutch. After the war he was placed on the famous Russian course at Cambridge, which inspired in him a love of the country and the culture, and sent to Berlin to spy on East Germany.In 1948 he was chosen to go to Korea to establish a network of agents. While he was there, as vice-consul in Seoul, the Korean war broke out and the capital was overrun by the Communist North Korean army. In the company of other diplomats and missionaries, Blake was evacuated north and interned and witnessed what he claimed convinced him that he should work for the other side: “It was the relentless bombing of small Korean villages by enormous American flying fortresses. Women and children and old people, because the young men were in the army We might have been victims ourselves. It made me feel ashamed of belonging to these overpowering, technically superior countries fighting against what seemed to me defenceless people I felt I was on the wrong side …

that it would be better for humanity if the Communist system prevailed, that it would put an end to war.”He contacted the KGB and offered his services. For the next nine years, wherever he was posted for MI6 – Vienna, Berlin, Milan, Beirut – he met his KGB case officer every three weeks to pass over information.In 1960 a senior Polish intelligence officer defected to the West and uncovered many major spies in the UK, including Gordon Lonsdale and Peter and Helen Kroger. In April 1961 Blake was recalled to London from Beirut where he was learning Arabic and accused of working for the Soviets.Harold Macmillan’s Conservative government was highly embarrassed by this new failure of British intelligence. The prime minister suggested to Dick White, MI6’s head, that Blake’s treachery should be kept quiet and he be offered immunity from prosecution in return for a full confession “The government could fall on this,” he told him. White refused to cooperate; he later said Blake had done more damage than Philby, the most notorious traitor of the period.Blake’s trial was held in camera, and he was found guilty. The maximum sentence for passing official secrets in peacetime was 14 years.

However the judge divided his spying into separate episodes in three countries and sentenced him to three periods of 14 years, to run consecutively. At the time, 42 years was the longest sentence ever passed in a British court. The actual damage he did is still classified.The severity of this sentence was one reason that Blake found prisoners to help him make his 1966 escape by way of a rope thrown from outside. He later expressed regret for those agents he betrayed, and also personal regrets for the pain he caused his unwitting first wife and family. (He remarried in 1969.)However, he has no regrets for his support of Communism: “The Communist ideal is too high to achieve .. and there can only be nominal adherents to it in the end.