In the dark days that followed the fall of France a new volunteer fighting force was hastily improvised to wage a secret war against Hitler's armies. This force was called the Special Operations Executive (SOE) and their mission was sabotage and subversion behind enemy lines.
Sabotage meant blowing up trains, bridges and factories whilst subversion meant fostering revolt or guerrilla warfare in all enemy and enemy-occupied countries. On July 16, 1940, Prime Minister Winston Churchill appointed a civilian, Hugh Dalton, to be SOE's political master and then promptly ordered him to 'set Europe ablaze!'
Bold words indeed from Churchill considering that SOE only had a few agents in the field and no effective wireless communications.
In November 1940, as the Luftwaffe pounded Central London, SOE set-up its first headquarters in two family flats off Baker Street. From this unlikely venue SOE began to recruit men and women to fill their ranks.
Senior staff in SOE were invariably ex-public school and Oxbridge, but the agents came from all walks and included a former chef, an electrician, several journalists and the daughter of a Brixton motor-car dealer.
At the same time SOE's new head of training and operations, Colonel Colin Gubbins, began to requisition properties across the country to act as agent training bases. In mansions that stretched from the Highlands to the New Forest agents were taught how to kill with their bare hands; how to disguise themselves; how to derail a train; and even how to get out of a pair of handcuffs with a piece of thin wire and a diary pencil.
If an agent survived these tests and a gruelling parachute course they were ready to go.
To give agents an edge in combat SOE employed budding scientists to invent unique weapons of war.
At The Frythe, a secluded house near Welwyn Garden City, Hertfordshire university graduates invented devilish devices such as the single-shot cigarette pistol and the Sleeping Beauty - a submersible canoe. SOE workshops also created carborundum - an abrasive grease when smeared on the right spot could bring a locomotive to an immediate standstill.
In North London, The Thatched Barn, a former roadhouse, became the headquarters of the ingenious Camouflage Section run by film director Elder Wills. Here an army of ex-prop makers were put to work creating countless illusions out of papier maché or plaster - many of them deadly!
One tree trunk mould might conceal radio equipment but another shaped like a piece of camel dung hid a booby trap that could blow the tyre off an enemy truck.
Other branches of this backroom operation included the False Documents Section where agents collected their bogus identities and even a fashion company that outfitted agents with suits and dresses cut to the Continental style.
The Secret Intelligence Service (SIS) - now known as MI6 viewed SOE with great suspicion.
Head of the SIS, Sir Stewart Menzies, stated repeatedly that SOE were 'amateur, dangerous, and bogus' and took it upon himself to bring massive internal pressure to bear on the fledgling organisation. SIS did not want SOE disrupting their agents intelligence-gathering operations by blowing up bridges and factories.
Bomber Command also despised SOE and resented having to loan aircraft for 'unethical' clandestine missions. They wanted to win the war by bombing Germany to its knees.
But with Churchill as their guardian SOE survived and lived to fight another day.
SOE's first headline success came in June 1941 when agents blew up the Pessac power station in France with a few well-placed explosive charges. The precision blast crippled work at a vital U-boat base in Bordeaux, and brought the all-electric railways in this region to an abrupt halt.
News of this triumph reverberated throughout Whitehall and put SOE firmly on the map - proving that you did not need a squadron of bombers to disrupt the German war machine.
This operation led to hundreds more in Europe and in the Far East against the Japanese.
Czechoslovakia 1942 - an SOE hit squad assassinated Himmler's deputy, Reinhard Heydrich, with a grenade.
Greece 1942 - SOE agents blew up the Gorgopotamos rail bridge, which carried vital supplies for Rommel's desert army.
Norway 1943 - SOE agents destroyed the heavy water plant at Vemork, ending the Nazi atomic bomb programme.
Often SOE operations resulted in reprisals against the local population. After the killing of Heydrich, the SS exterminated 5,000 men women and children in two villages near Prague.
To avoid retribution, SOE carried out 'invisible sabotage', which left no trace and implicated nobody. One example is the sending of a supply train, loaded with tanks, to the wrong destination - using only a forged document.
The life expectancy of an SOE wireless operator in Occupied France was just six weeks...
Complicated coding and decoding procedures left Wireless Telegraph (W/T) operators with no choice but to transmit for long periods of time. This gave German military intelligence, the Abwehr, ample time to find their quarry using radio detection vans.
The Germans knew that W/T operators were the weak link in the chain of any agent network. In Holland the Abwehr played the Englandspiel - 'the match against England' - by controlling the wireless traffic of a captured SOE operator. Dozens of agents fell straight in to enemy hands as result - most were eventually shot.
The Abwehr were a deadly foe, but not as ruthless as the Gestapo or the SS Sicherheitsdienst, who tortured their victims before execution.
By D-Day on 6 June, 1944 SOE had become a feared organisation that could strike the enemy anytime, anywhere.
Agent networks now stretched across Occupied Europe, linked to an army of resistance fighters. When the Allies landed, SOE struck with venom.
One immediate target was the 'Das Reich' 2nd SS Panzer Division, which began to march north through France towards the Normandy beaches. SOE agents siphoned off all the axle oil from the division's rail transport cars, and replaced it with abrasive grease - all of them seized up.
On the roads Das Reich columns were constantly ambushed, allowing the RAF to wreak havoc. This crack division was delayed for 17 days, by which time the Allies had a firm foothold in France.
SOE kept the pressure on the enemy in the mountains of Yugoslavia and northern Italy. In Genoa, 600 partisans took the unconditional surrender of 12,000 German troops, with SOE at the centre of the negotiations. The price of freedom was high, but SOE accomplished their mission to the letter.
In May 1945 General Eisenhower wrote that 'the disruption of enemy rail communications, the harassing of German road moves and the continual and increasing strain placed on German security services throughout occupied Europe by the organised forces of Resistance, played a very considerable part in our complete and final victory.'
With no war to fight, SOE survived until January 1946 before being disbanded forever.