Like many people, Fiona Bruce dreams of finding a rogue in her family tree. “Dull is not good,” jokes the newsreader and presenter of Antiques Roadshow at the start of her episode of Who Do You Think You Are? “What would be great, I suppose, is if we got some kind of a great character, or some sort of, I don’t know, a mass murderer, or a stripper, or someone extraordinary.”

In the event, there are no notorious killers among her forebears.

However, Fiona does discover a genuine rascal, tragic tales from the First World War and, as you might expect from her name, strong links to Scotland through her father John, an “amazing role model” who started out at Unilever as a post boy and ended as managing director.

The first figure that Fiona wants to learn more about is her great grandfather, Frederick Charles Crouch, an artilleryman who started in the ranks but became an officer when the army needed experienced men in the First World War. Frederick died from shrapnel wounds at Ypres in 1917. A family story suggests he was the only man who didn’t duck as a shell came in. Can that really be true?

In search of clues, Fiona visits Christ’s Hospital, a charitable school that provided Fred’s eldest son with a public school-style education. In her application, his widow Isabella talks of Fred being in hospital for nine months with shell shock. Professor Edgar Jones, a psychiatrist at Maudsley Hospital, tells Fiona that “war-weary soldiers tend to be fatalistic”. Perhaps Fred failed to take cover simply because he’d lost the will to go on after seeing so much horror.

Fred joined up young, apparently because he had endured an unhappy home life. His father, William, was a photographer. When Fiona sees adverts in trade directories held at the Brighton History Centre, it seems he must have been successful. And yet, as Fiona says prophetically, “There’s something about [William] that doesn’t quite add up.”

As she traces William’s life in London, Bexhill-on-Sea and, ultimately, Edinburgh, where he died from “illnesses you’d associate with poverty” in 1907, it becomes clear William was a conman. According to an article in the British Journal Of Photography, copies of which are held at the British Museum, he charged pupils who wanted to become photographers. But there was no training and William appeared in court, charged as a fraudster.

How much did such a chaotic life affect young Fred? “I find [William] quite entertaining,” says Fiona, “but the impact of his behaviour on [his children] is pretty devastating.”

Fiona also wants to know more about her Scottish roots. Heading for the village of Hopeman on the Moray Firth, the village where her father grew up, Fiona hears how her trawler skipper great grandfather, John Bruce, was killed while on minesweeping duty during the First World War. With John’s death, Fiona’s great grandmother, another Isabella, was left to raise eight children. It must have been a tough life, although not as harsh as that endured by her 3x great grandfather, George Bruce, another rogue. Poor relief records call him “a drunken creature,” and he died of malnutrition.

Fiona says that what she's learnt through her search has not only brought the past alive, but also provided a new perspective on her father’s success. “I feel incredibly proud of my dad,” Fiona says. “And when I come back [to Hopeman, a village in Scotland] and I see what he started from and what the rest of them started from, it’s a really amazing thing.”