The Auxiliary Unit was Britain’s secret army if Britain was ever invaded. The Auxiliary Unit comprised of men from the Home Guard who were to act as resistance fighters behind enemy lines once an invasion had taken place.

The Auxiliary Unit was the idea of Major-General Colin Gubbins, a top intelligence officer in the British Army. He wanted a secret resistance unit set up in advance of an invasion so that should an invasion ever come, resistance would start immediately when the Germans were least prepared to cope with it. Major John Forbes was given the task of visiting local Home Guard commanders and finding out from them who their best men were. Forbes introduced the idea of the unit with the phrase:

“I want volunteers for a very dangerous job.”

The most important requirements for the volunteers was an expert knowledge of their own locality, a degree of physical fitness and an ability to keep what they were doing a secret. In fact, all those who joined the Auxiliary Unit were made to sign the Official Secrets Act. Men in the Auxiliary Unit were kept separate from the Home Guard.

The men who volunteered for the Auxiliary Unit were trained at Cole’s Hill, Wiltshire, in how to make OB’s – Operational Bases. These would be their underground homes once an invasion had started and were built in the area where the men lived. OB’s allowed the men to disappear into the countryside. OB’s were built fifteen feet down into the ground with walls of brick and concrete to ensure that they were built to last. The work was done by men from the Royal Engineers brought in from outside so that they would have no idea as to what they were building. Each OB had a blast wall below the entrance to stop the blast of any grenades that may have been thrown in. Each OB housed between 6 to 8 men and they were self-contained units and would be the homes of men in the Auxiliary Unit once the Germans had invaded. The OB’s allowed each group of men to work behind enemy lines to act as saboteurs etc.

Men in the Auxiliary Unit were expected to last for about two weeks before they were either captured or killed. In that time they were expected to do what they could to disrupt the supply lines of the Germans by blowing up bridges, rail lines, air strips etc.

“Looking back, it was looked upon as part of a suicide mission but we didn’t feel that at the time.” Forbes

There were about 3,500 men in the Auxiliary Unit. On September 7th, 1940, ‘Codeword Cromwell’ went out across the country – the signal that invasion was imminent. As a result of this, the men in the Auxiliary Unit went to the OB’s and waited. However, it proved to be a false alarm. On the orders of Winston Churchill, the unit received the most modern weaponry available – machine guns, explosives etc.

It was expected that anyone wounded in the unit would be shot by his other comrades rather than let him fall into the hands of the Germans. The men were also issued with suicide pills to be taken if they were captured.

Such was the importance attached to the unit that they had permission to deal with collaborators.

  “We had authority if we found collaborators in any village around us, to shoot them, kill them.” 

Men in the unit were also expected to ignore German reprisals against their actions amongst people in their own locality.

How effective the Auxiliary Unit would have been is open to speculation as the invasion never occurred and the unit was never called upon to do what it had been trained to do.