The British penchant for eccentricity seems to flourish in wartime. How else to explain boffin Geoffrey Pyke's plan to construct a two-million-tonne aircraft carrier from ice and wood pulp before the invasion of Normandy in 1944 - and the enthusiasm that Churchill and Mountbatten showed for the project? Habbakuk, as the scheme was called, never came to fruition, although numerous other less hare-brained ideas played a large part in the Allied victories in the two world wars.

More importantly, the thinking that was prevalent in the early stages of the first world war - that 'gentlemen did not read somebody else's mail' - was soon dispensed with as the British secret service grew from a minor department with little influence into an important factor in all operations.

Nicholas Rankin's Churchill's Wizards: The British Genius for Deception 1914-1945, skates over four decades of British skulduggery in all its many forms, from the fake trees erected as observation posts in the battlefields of Flanders to the Nazi secret agents captured in England and subsequently turned against their former employers.

Rankin freely admits to a love of theatre, stating that the audience willingly suspends its belief to enjoy the performance. He writes: 'Deception ... in ordinary life is wrong because it corrodes trust, which is the basic glue of human relationships. But deceiving your enemy in wartime is common sense. If the war is just, then deception is justified.'

The book's title is slightly misleading because not all the spooks and scientists were directly connected to Churchill. It rattles along in anecdotal style, essentially a history covering 30-odd years with the emphasis on prototype James Bonds and Qs.

Much of the material has been covered in previous books, or films such as The Man Who Never Was, which dramatised the 1943 plot to dump a body dressed in Royal Navy uniform and carrying misleading documents off the coast of Spain, where it was intercepted by Nazi sympathisers.

Rankin brings the story up to date, noting that Glyndwr Michael, whose corpse it was, is one of the few civilians whose name features on the Commonwealth War Graves Commission website.

Less well known is the spy Juan Pujol, a Spaniard who enlisted with the German secret service with the strict intention of becoming a double agent for the Allies.

His faked reports from England convinced the Nazi high command that the main thrust of the long-awaited invasion of France would be directed at Calais, so German units were held in reserve rather than being committed to repulsing the Allies in Normandy.

By the time the enemy realised their mistake, US general Dwight Eisenhower's forces had established a firm bridgehead and the end of the war was in sight.

Pujol, who was subsequently awarded the MBE, emigrated to Venezuela, but returned to Britain in 1984 where he was personally thanked by the Duke of Edinburgh for his valiant clandestine work.

The most entertaining part of Wizards concerns the bevy of Britons who in one fashion or another lent themselves to the shadowy existence of the intelligence services. T.E. Lawrence was only too happy to blend into the role of roving Arab prince; Ian Fleming (above), creator of 007 and a British intelligence agent in reality, makes a not unexpected appearance; even film star David Niven was involved in planning raids across the Channel, although he found himself in trouble with the authorities, who failed to spot the double entendre in a telegram to a girlfriend in which he promised to bring his 'secret weapon'.

But it was really those behind the scenes who effected the greatest changes. Pre-Raphaelite artist Solomon J. Solomon, for example, was never given any award, but he was the brains behind pioneering the art of camouflage in the first world war, saving countless lives and turning the tide of victory.