Tinker Tailor Soldier Spy author John le Carre, who cast flawed spies on to the bleak chessboard of Cold War rivalry, has died aged 89.
David Cornwell, aka John le Carre, died after a short illness in Cornwall, England, on Saturday.
He is survived by his wife, Jane, and four sons. The family said in a brief statement he died of pneumonia.
"Very sad to hear the news about John le Carre," said Richard Moore, the chief of Britain's MI6 foreign intelligence agency.
By exploring treachery at the heart of British intelligence, le Carre challenged Western assumptions about the Cold War.
Le Carre's heroes were trapped in the wilderness of mirrors inside British intelligence which was reeling from the betrayal of Kim Philby, who fled to Moscow in 1963.
"It's not a shooting war anymore, George. That's the trouble," Connie Sachs, British intelligence's alcoholic expert on Soviet spies, tells spy catcher George Smiley in the 1979 novel Smiley's People.
"It's grey. Half angels fighting half devils. No one knows where the lines are," Sachs says in the final novel of Le Carre's Karla trilogy.
The Cold War, for le Carre, was A Looking Glass War (the name of his 1965 novel) with no heroes and where morals were up for sale - or betrayal - by spy masters in Moscow, Berlin, Washington and London.
Such was his influence that le Carre was credited by the Oxford English Dictionary with introducing espionage terms such as 'mole', 'honey pot' and 'pavement artist' to popular English usage.
British spies were angry that le Carre portrayed the MI6 Secret Intelligence Service as incompetent, ruthless and corrupt. But they still read his novels.
David John Moore Cornwell was born on October 19, 1931 in Dorset, England, to Ronnie and Olive, though his mother, despairing at the infidelities and financial impropriety of her husband, abandoned the family when he was five.
At the age of 17, Cornwell studied German in Bern, Switzerland, where he came to the attention of British spies.
After a spell in the British army, he studied at Oxford, where he informed on left-wing students for MI5.
He taught at Eton and worked at MI5 in London before moving in 1960 to MI6.
Posted to Bonn in West Germany, Cornwell fought on one of the toughest fronts of Cold War espionage: 1960s Berlin. As the Berlin Wall went up, le Carre wrote The Spy Who Came in from the Cold.
Le Carre devoted himself to writing and the greatest betrayal in British intelligence history gave him material for a masterpiece.
The discovery, which began in the 1950s with the defection of Guy Burgess and Donald Maclean, that the Soviets had run spies recruited at Cambridge to penetrate British intelligence hit confidence in the once legendary services.
Le Carre wove the story of betrayal into the Karla trilogy, beginning with Tinker Tailor Soldier Spy (1974) and ending with Smiley's People (1979).
After the Soviet Union collapsed, leaving Russia's once mighty spies impoverished, le Carre turned his focus to what he perceived as the corruption of the US-dominated world order.