WATCH: The real story of how the SAS began

Myth inevitably surrounds the origins of the SAS, but Tom will cut through it, exploring the ideas and characters that forged a new means of warfare from the wreckage of Dunkirk.

Co-hosted by Petworth Bookshop, the event will be in The Assembly Room, Chichester on Saturday, June 10, 7.30pm. Tickets: £20, livestream: £10. Tickets on https://festivalofchichester.co.uk/. Tom’s book Speed, Aggression, Surprise: The Untold Secret Origins of the SAS has been published by WH Allen at £20, available from Petworth Bookshop, Amazon and most bookshops.

Tom said: “The story of the formation of the SAS is well known and is now a major BBC TV series SAS Rogue Heroes.

"I knew from my own time in the military (I served as an officer in the British Army for eight years, including the SAS) that this story had a flaw. It was impossible that a new unit could have been created in the British Army from ‘the bottom up’ in the manner portrayed.

"I made my second discovery years later in my career in the film industry while in the National Archives researching another project: that the SAS’ first successful operation was not carried out by any of its founders David Stirling, Jock Lewes or Paddy Mayne, but by a fourth officer called William Fraser. When I dug deeper, I discovered this man was the most successful of the original SAS officers, decorated for bravery three times, twice awarded the Military Cross and the Croix de Guerre, but I had never heard of him.

"This led to me researching the story further and, in 2020, sitting down to write a more extensive narrative about the formation of the SAS. What inspired me most was that the two heroes of my book – Dudley Clarke and William Fraser – had, for different reasons, never been able to tell their own story. This book should appeal to anyone who wants to know more about how and why the SAS, the world’s premier special force, came into being. A sequel is in the pipeline.”

It's a fascinating tale: “In the Second World War the SAS’s function was to act independently behind enemy lines, the Germans and the Italians, to destroy or disrupt strategic targets.

"They were very heavily linked to deception plans during the war. With the physical destruction side of things in North Africa they destroyed a lot of German aircraft and then a bit in Italy. Italy for the Allies was a bit of a struggle but once you get to France then the SAS really come into their own disrupting German communications and preventing Panzers from coming up to the front.”

The Official Secrets Act means that we can't know too much about what they are up to now. As Tom says there is a watershed after which the Act applies, but the wartime activities are not covered by the Act and this is the story he tells.

Tom started writing for film after leaving the army in 1997. His film The Patrol won the Raindance Film Festival in 2014.​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​