The Duke (left) & archaeologist Harvey Sheldon
Not many people could imagine finding a massive medieval church buried underneath their garden. But then, most people could not imagine living in the stately home and surroundings of Syon Park in West London where such a discovery has been made.
His Grace the 12th Duke of Northumberland, or Ralph Percy as he is known by good friends, can certainly picture himself living in Syon Park; his family and ancestors have been using the grand residence as their London base for over 400 years.
Visitors approaching Syon House's imposing façade may well think it is an unlikely location for a large archaeology project. Set within lovingly manicured gardens, it is exactly the sort of place you would expect to see in lavish costume dramas.
Indeed, Gosford Park, The Madness of King George and The Avengers are just some of the films that have used Syon House for location filming.
A gardener's hunch
Walk through the regal front door, through the splendid courtyard with its water fountains and you are soon standing on the back terrace gazing over, well, three large holes in the ground.
You're thinking the gardener must have a lot to answer for and, in a way, you'd be exactly right.
The Duke's family has lived at Syon Park for over 400 years
"We'd known for some time from the historical records that there had been this very large Abbey on the site at Syon," says Head Gardener, Topher Martyn.
"However, we knew very little about where it might have been on the site and what it looked like."
Bringing in the experts
Acting on his hunch, Topher Martyn managed to persuade Channel 4's Time Team to conduct some preliminary excavations in 2003.
What they have eventually discovered was a monumental church equal in size to Salisbury Cathedral, a series of outbuildings, graves and a stunning water feature that was likely to be the centrepiece of a formal garden, perhaps built by Henry, the 9th Earl of Northumberland in the 17th Century.
By any standards it was a remarkable find. It was time to bring in the experts.
Artist's impression of the church
Harvey Sheldon of Birkbeck College, is the Director of the Excavation overseeing work on the site today. He leads a team of students, volunteers and enthusiasts who are busying themselves in the three large pits. For one month each summer, from mid-June to mid-July, the college encourages members of the public to sign up for archaeology training camps.
Arrival of the Duke
Those that have taken to trouble to get their hands dirty on this particular morning are in for an unadvertised treat: The Duke is visiting to inspect the proceedings. After all, they are digging up his garden.
The Duke cuts an unassuming figure. His appearance is low-key and free of the pomp and circumstance that you might associate with someone who is the patriarch of one of the most important historical families in British history.
After he is given a brief guided tour of the site by Harvey Sheldon, The Duke disappears just as suddenly as he had appeared. But not before he has answered a few questions from BBC London.
Quizzing the Duke
What was your initial reaction when you found out about the extent of the remains that were discovered in your garden?
"I thought it was rather exciting actually
It's an area of the garden that isn't used very often. I am quite interested in archaeology
I studied history at university so it has been good to see the other side of it: The direct form of history."
How does he feel about Birkbeck turning his grounds not just into a giant classroom, but also inviting the general public as well?
"We're quite used to it and enjoy it."
And, what does he plan to do with the remains?
"I hope they will be put back and be here forever."
The site is open to students and the public
Despite being one of the richest men in the country, Ralph Percy comes across as a shy man who doesn't court unnecessary attention. Unfortunately for him hiding in the background isn't so easy when you are a Duke and your main home, Alnwick Castle, also doubles up as Hogwarts in the Harry Potter movies.
Anyway, he says his goodbyes and is gone.
Digging for answers
Syon Park might belong to The Duke, but for all intents and purposes, Harvey Sheldon is the man in charge of the archaeological dig. And he is using this opportunity not just to learn more about the past but also to train up future archaeologists.
"We try to teach students what is involved in excavating a site, how you remove finds, how you do drawings, how you make notes and how you record it," he tells BBC London. "Whether they are beginners or have some experience, we hope they develop their understanding and capabilities."
What's going to happen to the remains that you find here?
"What we do is backfill every year which protects the remains. We have two options really. We could mark out the remains in the ground or, if the estate wished, you could preserve them physically and let the public look at the real remains. But that's really a question for the estate to decide."
As Harvey and his army of students and volunteers only get to work on the site during the summer months, it could be a programme that continues for several more years. There is plenty of work to be do. Relatively little is known about the details of the church, monastic buildings and the gardens that have been discovered.
There are three digs on the site
Among the more exciting discoveries has been several preserved skeletons in burial grounds. One male torso found close to an elaborate structure has given rise to speculation that it could be the remains of someone significant: Thomas Stanley, 2nd Earl of Derby and step-grandson of Margaret Beaufort, mother of Henry VII, who was buried at Syon in 1521 aged 37.
The truth, perhaps, has been lost in the ground forever, but that won't stop Harvey's team of archaeologists from digging for the answers.