Following the Thread: The Road to 'An Axe and Four Balloons'

I had never set out to write military history. I'd left the Army, run a private security company, then sold it - I'd had enough of being in the field. Then, after moving down to Devon, completely coincidentally, I went to have a look at the Dartmouth Museum.

It's a tiny little museum, and heavily naval, obviously - Dartmouth has played an important role in Britain's naval history for centuries, so you would expect it to be so. I'd met the curator during the Falklands War - he was a sailor - and he mentioned to me a story local to Dartmouth that he thought I should take a look at.

It was the story of the 15th Motor Gunboat Flotilla. Ostensibly this was a Royal Navy unit, although it actually had very little to do with the Navy: the Navy was simply its cover. The flotilla lived in plain sight - four gunboats and a mother ship lying in the River Dart - and everybody thought they were going out into the Channel at night to shoot up German shipping.

But they weren't at all.

Their real job was to take agents across the Channel into occupied France and bring them home again. It was a really interesting story, so I looked at turning it into a book and I found that, as well as enjoying the writing, I particularly enjoyed the research.

For example, during the course of writing, one person emerged as a hero: David Birkin, the flotilla's chief navigating officer and the father of the singer and actress Jane Birkin. Jane proved incredibly helpful during the research, and became a very good friend; she even introduced me to those members of the French Resistance who were still alive, because they had worked with the escape lines and thus with the 15th Motor Gunboat Flotilla.

It's a hell of a story, and it became my first book: A Dangerous Enterprise.

Then, during the course of the research for A Dangerous Enterprise, I had come across the name of a customer of the flotilla: an officer in the Secret Intelligence Service called Wilfred 'Biffy' Dunderdale. I couldn't resist the name, and the more I looked at him, the more I thought he was a really interesting fellow.

That's why I wrote the second book, which was Biffy's biography. It had never been done before. Nobody had ever really written about him, yet he'd had an extraordinary career, beginning at the age of seventeen in the Crimea and Ukraine - which seems particularly topical now. In 1926 he became one of the youngest ever heads of station for the Secret Intelligence Service in Paris and, amongst other things, he brought us the first Enigma code machine. He had collaborated with the French and with the Polish Intelligence Service and, in many ways, the Poles were well ahead of the codebreakers at Bletchley Park. A deal was struck whereby the Poles would give him a copy of the German Enigma machine, together with their ideas about how it worked, how it encrypted messages and how those messages might be decrypted.

However, the most important thing Biffy did, which hardly anybody knew about, happened during the collapse of France in 1940. By then he had become friendly with the French Deuxième Bureau, the country's military intelligence service. When France fell, its officers were ordered to move to Vichy and become the Vichy Intelligence Service - in other words to work with the Germans.

They did go to Vichy, but they secretly swore allegiance to the Free French and, via Biffy, to the British Government. Basically they said to him, 'Get us a radio and we're back in business'.

People often ask about the relationship between the British and the Free French, and whether it caused problems for intelligence work. The Secret Intelligence Service was actually very clever about it. They told Biffy, 'We want you to run the French Section as well as the Polish Section, but de Gaulle must never know.' At the same time, they had somebody else working directly with de Gaulle, so there were effectively two French sections operating alongside one another. Between them they gathered a remarkable amount of intelligence, while Biffy continued to run his own networks. He really was quite a character.

Biffy stayed in the Service until 1959 before retiring to New York, although he never entirely stopped working. After the damage done by Kim Philby and the Cambridge Five Soviet spy ring, Britain's intelligence services had something of an image problem. Biffy helped to rebuild those damaged relationships with America by demonstrating that they weren't all that bad after all.

That was the second book: A Suspicion of Spies: Risk, Secrets and Shadows - the Biography of Wilfred 'Biffy' Dunderdale.

Now to explain the route to third book.

One of Biffy's agents was a chap whose cover name was Goodfellow, who happened to be the grandson of Ferdinand de Lesseps, the engineer behind the Suez Canal. That was interesting enough in itself, but after the book was published somebody got in touch with the publishers and introduced themselves as Mark de Lesseps, Agent Goodfellow's son.

Of course, I rang him up and said, 'We should have been having this conversation a year ago!' I arranged to see him in Burgundy and, during the course of the day, Agent Goodfellow's grandson asked me what I knew about his grandfather and an SAS operation in the Vosges Mountains called Operation Loyton.

I admitted that I didn't know much about it - Operation Loyton was a failed SAS operation behind enemy lines, where a unit of almost a hundred men was trapped, and thirty-one of them were illegally executed, with heavy reprisals inflicted on the locals. But what surprised me was that Goodfellow, who had worked in Biffy's office in London and so knew all sorts of military secrets, would be behind enemy lines and then have to escape. Yet it turned out that not only had he done that, but he'd already been on a couple of operations in Brittany with Biffy.

Serendipitously, after I returned from Burgundy, a very good friend reminded me that my friend's wife's maiden name was Franks: the granddaughter of Brian Franks, who had also worked with Biffy during Operation Loyton. More than that, Franks was one of the founders of the SAS who, when the regiment was disbanded at the end of the war, fought very hard to reinstate it. So, when my friend asked that I write Brian Franks's biography, Operation Loyton seemed a good place to start. There were too many strange coincidences to ignore it.

The new book is therefore the story of Franks's life, called An Axe and Four Balloons: The Biography of Brian Franks DSO MC, the Man Who Saved the SAS. You'll have to buy the book to find out why, but the title comes from an unusual story in itself. Yet despite Franks being such a fascinating man, nobody has really written about him before - just like Biffy. There must be hundreds of books about David Stirling and thousands about the SAS, but nothing about Brian Franks.

Thanks to that chance visit to Dartmouth, I've now written three books, all about famous men you've never heard of.

An Axe and Four Balloons: The Biography of Brian Franks DSO MC, the Man Who Saved the SAS is published on 3 September by Barbreck. You can purchase it here.

Images courtesy of the Franks Family Archive.