"[Cecil Clarke] is one of the most extraordinary members of Churchill's inner circle. He had a highly devious brain. He was able to think outside the box, in modern parlance. And he came to Churchill's attention because of the extraordinary machines he'd been building, and he was asked to try and develop a magnetic mine that could be used underwater to sink the great ships of Hitler's new fleet. And he developed this thing called the limpet mine, which could be stuck onto the underside of any of Hitler's battleships, blow up and sink the ship."

"He was a pillar of the establishment, but he also, throughout his career, he'd always supported the maverick, the eccentric, the unusual. And I think in the summer of 1940, he realized that, because there was no hope of tackling the Nazi war machine head on, that he needed to think of more eccentric solutions to this grave crisis that was facing the country. He began to turn to people who could dream up these creative solutions to trying to destroy, or at least hit back in some small way, at Hitler's army."

As Hitler set his eyes on sacking Great Britain, Prime Minister Winston Churchill knew there was no chance of defeating him by conventional means. So Churchill created a top-secret organization devoted to sabotage and guerrilla warfare.

"He realized that, because there was no hope of tackling the Nazi war machine head on, that he needed to think of more eccentric solutions to this grave crisis that was facing the country."

"Colin Gubbins, was, from a very early age, he'd been interested in unorthodox warfare. He had served in the trenches of the First World War, seen the horror of war in the trenches. He had then served a very dirty war against the Bolsheviks in Russia. He'd then gone to fight against Sinn Fein in Ireland. And he'd studied all sort of unorthodox fighters, particularly Al Capone and his Chicago gangsters. He thought the way they used their Tommy guns was absolutely brilliant. And he was brought on board to set up an organization — highly secret organization — whose exclusive goal was really to explore guerrilla warfare and sabotage and how Hitler's army could best be targeted."

On the debate over "ungentlemanly warfare"

"In 1940, there was a debate in the House of Commons about how Britain should fight the war against Hitler. And, it's extraordinary when you hear member of Parliament after member of Parliament stand up and say, 'War should be fought by the rulebook,' you know, that war was a little bit like cricket, only it used weapons. But others begged to differ, and Colin Gubbins was one of them. He said no, when you're fighting against an enemy as devious and nasty and dangerous as the Nazis, then you simply had to tear up the rulebook, and anything went, basically."

Book Excerpt: 'Churchill's Ministry Of Ungentlemanly Warfare'

By Giles Milton

Eric Sykes and William Fairbairn had first come to the attentions of the War Office a year earlier when they pitched up unannounced in Whitehall, having just arrived from the Far East. Both were close to retirement age and had come to offer their services in the fight against Nazi Germany. At first glance they were an unlikely couple of recruits, best suited, perhaps, to patrol duty in the Home Guard. Dressed in khaki, and striding suburbia with pitchfork and spade, they would have at least been made to feel they were playing a part in the war against Hitler.

But they arrived in London with such an incredible story (and curriculum vitae to match) that they could not be easily ignored. The first of the men, Eric Sykes, was known to his friends as Bill, a reference to Dickens’s famously shady character. He was stocky, with pebble-glass spectacles and a dimpled smile: he looked as if he couldn’t hurt a fly. One acquaintance said he had the ‘manner and appearance of an elderly, amiable clergyman’. Others were ‘lulled by his soft tones and charmed by his benevolent smile’. But Sykes was neither benevolent nor a clergyman. He was an expert in silent killing – chilling, ruthless and clinical – and a man whose every sentence was said to end in the words, ‘and then kick him in the testicles’.

His previous employment had been in Shanghai, where he had worked as the representative of two American firearms companies, Colt and Remington. He was a crack shot, arguably the finest in the world, and his speciality was shooting from the hip. One who watched him in action was astonished to see him spin round, gun in hand, ‘with his back facing the target and hit the bull’s eye from between his legs’.

Sykes’s comrade-in-arms was William ‘Shanghai Buster’ Fairbairn. Similarly portly, and myopic to boot, he gave the impression of being ‘smaller than he really was, with his long arms and the slight stoop that gave him the aspect of a monkey having learned to walk like a man’. Like Sykes, he had the air of a Church of England chaplain. ‘His horn-rimmed spectacles and benevolent expression earned him the nickname “The Deacon”.’19 Yet he was a deacon whose sermons had a nasty sting in the tail: ‘Kill or be killed,’ was his catchphrase.

Fairbairn’s conversation was generally limited to two words, ‘yes’ and ‘no’, and he didn’t allow his discussions on human anatomy to stretch his vocabulary unduly. ‘He had never attempted to find out the names of the various bones or muscles, and throughout his short, jerky explanations he would merely refer to “this bone” or “that muscle” and point it out or touch it with his finger.’

His friends knew him as Delicate Dan, but he referred to himself as Mister Murder-Made-Easy. He would smile benevolently as he taught his pupils ‘how to break a man’s neck or smash his spine across your knee’.

Fairbairn was the elder of the duo, a fifty-eight-year-old miscreant who had run away from the family home at the age of fifteen and lied his way into the Royal Marines. Initially posted to the British Legation in Seoul, he won himself a place on the bayonet fighting team and then honed his skills in contests against Japanese experts in martial arts. The Japanese taught him that the butt of a rifle was every bit as effective as a bayonet. Smashed hard into an opponent’s face, it caused such severe internal bleeding that death would rapidly follow.

Fairbairn had been headhunted for employment by the Shanghai Municipal Police in 1907, a position he was to hold for the next thirty-three years. The city was infamous for its armed gangsters, drug runners and violent criminals. Not for nothing was it known as the toughest city in the world. Fairbairn’s job was to quell gang warfare, a task he set to with such relish that there were some who wondered if he wasn’t a gangster himself. He rapidly established his Riot Squad, a team of 120 hand-picked men who were trained in what he called ‘Gutter Fighting’.

All his men were crack shots, but Fairbairn himself favoured close-range physical combat over the bullet. ‘His system is a combination of ferocious blows, holds and throws, adapted from Japanese bayonet tactics, ju-jitsu, Chinese boxing, Sikh wrestling, French wrestling and Cornish collar-and-elbow wrestling, plus expert know- ledge of hip-shooting, knife fighting and use of the Tommy gun and hand grenade.’

A lifetime of fighting had left its mark. He had a broken nose and a long scar that stretched from ear to chin. Yet most people were struck by ‘his flashing white teeth that no amount of punching had ever loosened’.

His principal interest in life, apart from fighting, was his prize goldfish. He had the finest collection in China – more than 100,000 in total – which he kept in specially constructed pools.

Fairbairn came to know Eric Sykes through his work with Colt and Remington. By 1926, he had drafted him into his Riot Squad, where Sykes swiftly proved himself a valuable addition to the team. The two men shared a passion for dirty killing and together wrote the seminal work on pistol shooting, Shooting to Live. This was followed by other books: All-in Fighting, Get Tough and Self-Defence for Women and Girls.

When Sykes and Fairbairn explained their skills to the War Office, it was immediately apparent that there was no place for them in the British Army. The idea of a good clean fight was anathema to them.

They were brought to the notice of Colin Gubbins, who immediately hired their services and sent them briefly to Brickendonbury Manor before dispatching them to the Highlands of Scotland. By the spring of 1941, they had become key members of his inner circle and absolutely crucial to his forthcoming operations.

Excerpted from CHURCHILL'S MINISTRY OF UNGENTLEMANLY WARFARE by Giles Milton. Copyright © 2017 by Giles Milton. Reprinted with permission by Picador, an imprint of Macmillan Publishers Ltd.