Talent pool that served both sides of the iron Curtain

Where does the secret service go to recruit spies? Cambridge, where the KGB used to hunt too. Kam Patel went there to meet an intelligence expert

Christopher Andrew leads the way to Corpus Christi's senior common room. A portrait of a young man, an air of defiance about him, hangs on one wall. Andrew gazes at the youth, "a very unsatisfactory undergraduate", he says, who flitted Corpus without settling his college bill. An inscription, in Latin, indicates that the portrait was painted in 1585. The young man went on to lead a colourful life, penning a "few very interesting plays". But the dramatist's career came to an abrupt and violent end when, aged 29, he was stabbed to death in a pub brawl in Deptford, London, while on a mission for the secret service of Queen Elizabeth I.

"His name was Christopher Marlowe," Andrew reveals, "he was Corpus's first spy. For Andrew, professor of history at Cambridge and an expert on the murky world of spies and secret services, the tale is a reminder of the enduring link between the university and intelligence services. Both current heads of MI5 (Stephen Lander) and MI6 (Richard Dearlove) are former Cambridge historians. Students on Andrew's final year history course on intelligence communities and governments in the 20th century are regularly treated to talks by leading figures from the secret services. MI5's Lander recently obliged with a review of secret service priorities past, present and future. "The only condition attached to his visit was that nothing he said would be made public," says Andrew. The 20th century saw the university transformed into a recruiting ground for some of the best spies and intelligence experts both for Britain, of course, but also for enemies of the state too. The "Cambridge Five" - Burgess, Philby, Blunt, MaClean and Cairncross - recruited by the KGB, were the most notorious.

Andrew, author or editor of a string of bestselling books on intelligence including The Mitrokhin Archive and For The President's Eyes Only, is steeped in Cambridge's intelligence culture. His own interest in the field began when working on his Phd in the mid 60s. Researching French foreign policy before the First World War he quickly realised the French must have broken secret German codes. He excitedly told his supervisor Harry Hinsley of his finding. "He just said: 'that is very interesting'," recalls Andrew. "I subsequently found out he had spent the entire Second World War code breaking at Bletchley Park," he says, laughing. Hinsley, vice chancellor of Cambridge University in the early 80s, died two years ago. In 1939, aged 20 and about to start his third year studying history, he was recruited to work at Bletchley Park, Britain's wartime codebreaking agency. He never finished his degree. "They simply recruited the brightest people they could find," says Andrew. "A third year history group working on intelligence today can connect with the idea that at their age Hinsley was actually doing it rather than studying it, says Andrew. At the end of the war Hinsley played a central role negotiating with the Americans the protocols that would govern the future sharing of intelligence between Britain and the United States. "It is the core of the "special relationship" between US and Britain in peace and in war. No two independent powers have shared more secrets in the history of the world because of it," says Andrew. Formal, systematic recruitment by British security services of students, especially those at Oxbridge, began during the Second World War. The KGB however were far ahead, having established a serious "talent spotting" programme, especially at Cambridge, in the 1930s. The gradual maturing of the competing programmes meant there was an extraordinary period at the beginning of the Cold War when Cambridge ended up providing some of the best talent to both sides of the Iron Curtain.

Andrew, 58, says he has "no problem" imagining falling in the mid - 1930s for the allure of the Soviet Union. It was a "deeply inglorious period in British history": the country was in the middle of a depression; Cambridge reflected the conservative attitudes of the time; the Labour Party had collapsed and British foreign policy was in a mess. This was in sharp contrast to the image being created by the first worker-peasant state in history and its insistence that all individuals, regardless of their background, had the right to fulfil their potential.

Andrew says: "That is such a seductive thing, and I understand how people fell for it, but as we know it bore no relation to the reality...I can see how the Cambridge Five, disillusioned with British society fell for it. You could ask how they could work for such a brutal one party state but of course that is the wrong question because what they worked for was the myth and mighty powerful it was too." Andrew says he has "no objection whatsoever" to (British) security services plying their trade on campuses. He says: "If you need intelligence services, you need to recruit, it is as simple as that." Some time ago at Corpus he had a room between two notable people: "On one side was the former talent spotter and on the other the current talent spotter and there I was in the middle writing a book about intelligence." Has he ever been asked to do some recruiting ? "No, curiously enough ," he replies, dead pan. He will only concede that when writing references for students he was "sometimes aware which of them were really going into the foreign office proper and which were destined for its "funny end"...same with MI5 and the rest of Whitehall." Nonetheless he boasts an unsually good relationship with the British security services, as demonstrated by his exclusive access to The Mitrokhin Archive.

Some academic researchers were irritated by the Government's failure to distribute one of the most extraordinary insights ever into KGB infiltration via the Public Record Office. Andrew however says: "It is simply would not have possible to place the whole thing in the public - not least because of the legal implications." When first informed of the archive and its content by people he "suspected were not from the gas board" his reaction was that it was so preposterous it might well be true. Smuggled into Britain by KGB archivist Vasili Mitrokhin when he defected in 1992, the material was published in last year's The Mitrokhin Archive: The KGB In Europe and the West. Jointly edited by Andrew and Mitrokhin among the many startling revelations in the book is that an 87 year-old grandmother, Melita Norwood, now living in London, spied for the KGB under the codename Hola. The Crown Prosecution Service decided not to pursue a prosecution of her. Andrew says: " I have to say, not entirely logically, that I'm rather relieved Norwood wasn't prosecuted. It was all a long time ago and she set out with good - though hopelessly mistaken - intentions. What sticks in my throat is that she should - if correctly reported - still think she was right to do what she did. Why can't she simply say, 'I did what I thought was right at the time, but now realise I was terribly mistaken'?" The second volume of The Mitrokhin Archive is scheduled for publication in two years time and promises equally startling revelations about KGB infiltration of the rest of the world - India and Latin America in particular. Andrew is convinced that despite the ending of the Cold War national security services around the world, certainly at home, will continue to thrive.

He says: "Human nature ain't changed much throughout the history of species...all the evidence suggests a continuation of its more undesirable characteristics. The idea that a century which included the likes of Pol Pot, Hitler, Stalin, and Mao Ze Dong during his crazed period, is suddenly going to be followed by perpetual peace and tranquillity is just absurd."