Antiques Roadshow expert stunned by valuable artefact from WWII hero who saved St Paul's

Antiques Roadshow expert Mark Smith was privileged to meet a relative of an inspiring soldier who committed an act of incredible bravery during the Second World War.

The popular BBC programme was visiting Stephens House & Gardens in north London this week in a new episode that aired this Sunday evening (31st August).

While curio connoisseurs perused the likes of a gold ring discovered in an orchard and an iconic image from David Bowie's heyday, it was an intriguing relic from WWII that caught Mark's attention.

It's also the segment that will likely have viewers reaching for the tissues, as it involves an inspiring act of bravery that ensured the iconic St Paul's Cathedral is still standing today.

Mark introduced the items: "We have on the table a bomb fuse and a George Medal. I have a feeling I know where this story is going to go."

The expert then asked for an introduction to Ronald Smith, a man in uniform in a black and white photograph also being presented, whom the guest revealed was uncle to the husband of one of his cousins.

Ronald joined the Navy at the onset of the war and later volunteered to become a Bomb Disposal Officer.

He would later be awarded the George Medal, which Mark describes as "a very high-up gallantry award. Above it only the Victoria Cross and the George Cross.

"Now, this chap here is actually quite a famous Bomb Disposal Officer," Mark continued, "because this is the man who diffused the German parachute mine at St Paul's Cathedral in April, 1941.

"Without him that day, that landmark that we all know so well, people all over the world know, wouldn't actually, probably, be standing today.

"Now, as with all gallantry medals, there is always a citation. And I have the citation here for Ronnie's day out."

Mark was visibly quite emotional as he recalled Ronald's inspiring story and continued to read the incredible tale of his bravery that ensured the survival of one of the UK's most beloved landmarks.

"'On the 17th April 1941 an unexploded mine lay in the churchyard of St Paul's Cathedral, about three yards from the cathedral itself'," he began.

"'The mine was completely covered by the parachute, which was impossible to remove. And so, Lieutenant Smith had to crawl underneath and inside the parachute to get at the mine.

"'In this dark and difficult position he commenced to unscrew the disc from the bomb, prior to fitting the gag', which is a device for rendering the fuse inert.

"'Before he was able to fit the gag, a large fire engine was driven past at speed only some 10 yards away. The vibrations sent up by the fire engine started the clockwork mechanism of the bomb fuse.

"'Under the best circumstances, Lieutenant Smith had 17 seconds to make good his escape. But very gallantly continued his operations and was able to insert the gag before the mine exploded.

"'Had the mine exploded, there is no doubt that the main part of the cathedral would have been devastated.' That's incredible."

Mark also shared that he has read that when Ronald was finally able to diffuse the mine, there were just two seconds left on the clock, which he admits is "terrifying" to contemplate.

When it came to the valuation, the guest was stunned when Mark revealed the collection could sell for as much as £15,000 - £20,000 at auction.

The guest was almost speechless as he gasped: "Wow, I never thought it was that much. Wow."

Antiques Roadshow is available to watch on BBC iPlayer.