In the background of almost every piece of footage of Britain's great wartime leader Winston Churchill, is an anonymous figure: his bodyguard, Detective Inspector Walter Thompson of Scotland Yard. This is the story of how these two very different characters met, and how the poor boy from London's East End saved his boss from an IRA assassination attempt.

Soon after he became Winston Churchill's personal bodyguard, Walter Thompson was given the challenge of keeping his boss alive during a visit to the Middle East. A leading British politician was a natural target for assassins, and on several critical occasions, Winston was rescued by one of the most enigmatic figures of the 20th Century - Lawrence of Arabia.

In 1929, Winston Churchill ceased to be Chancellor of the Exchequer, and Detective Sergeant Walter Thompson sadly stopped guarding the man he had come to regard as a friend. However, within two years, Winston's outspoken views had gained him fresh and deadly enemies. Walter was recalled, but the next threat to Winston's life came from a totally unexpected direction.

Having kept Winston Churchill safe from assassination during his US lecture tour in 1931, Walter Thompson soon left the police force. Out of office and increasingly at odds with his party, it also seemed that Winston's career was at an end. But a new and sinister force, which recognised Winston as its implacable enemy, was rising, and threats to Winston's life brought the two men together again.

During the 1930s, although he was out of office, Winston Churchill's outspoken opposition to Adolf Hitler and his Nazi regime made him a marked man. So much so that when war seemed inevitable, French Intelligence got wind of a German plot to assassinate him. Immediately Winston called his former bodyguard ex-Detective Walter Thompson out of retirement to protect him again.

As World War II began, Winston Churchill was brought back into the government after ten years in the wilderness. For his bodyguard Detective-Inspector Walter Thompson it was the beginning of the six most active and nerve-wracking years of his career. Within eight months his boss would be Prime Minister and risking his life on hair-raising trips to try to keep Britain's ally France in the war.

By June 1940, Britain was facing Nazi invasion. Prime Minister Winston Churchill's bodyguard Walter Thompson had at least managed to keep him safe during several dangerous trips to France. But the next year was to bring a host of new perils. For as the bombs rained down on, the one person to whose safety Winston gave no thought was himself, and Walter had to cope as best he could.

The entry of the United States into World War II meant an enormous increase in responsibility for Winston Churchill's bodyguard Walter Thompson. For the next three and a half years the two men were to travel almost 200,000 miles visiting the battle fronts and attending high-level conferences. Very soon, Winston was to come within seconds of assassination by a lone gunman.

A precarious trip to Moscow to visit Stalin is followed by victory for the 8th Army in North Africa. However, the Germans know that Churchill is travelling and try at least twice to shoot down his plane. His double is not so lucky…

Hitler's henchmen have devised a plan to kill Churchill, Stalin and Roosevelt at the Tehran Conference. Assassins are parachuted in carrying suicide bombs and it is up to Walter and the intelligence services to protect Winston's life from immediate danger.

Winston Churchill returns from Tehran in very poor health. So much so that his doctor expects him to die. Walter's devotion is such that he insists on staying at Winston's side on the crucial night and disaster is averted.

When Winston visits Athens he is supposed to stay at an hotel where Greek guerrillas have placed 1000 lbs of dynamite in a nearby sewer. They shoot at his plane and even fire on HMS Ajax his temporary home in Piraeus harbour.

It is VE-Day and Winston and Walter have several journeys to make through the jubilant crowds. Winston wants to walk and at the last minute is pulled on to the roof of his car by Walter who breaks a woman's arm whilst protecting his boss.