The theater that hosted William Shakespeare is the Norfolk Playhouse

A Norfolk theater believes it has discovered the only surviving stage on which William Shakespeare performed.

St George's Guildhall in King's Lynn is the oldest working theater in the UK, dating back to 1445.

During recent renovations, wooden floorboards were found beneath the existing hall, dating from the 15th century.

Theatrical claims documents show that Shakespeare acted in the theater in 1592 or 1593.

At that time, acting companies left the capital when theaters in London closed due to the plague. The Earl of Pembroke's men – thought to include Shakespeare – visited King's Lynn.

“We have the town's ledger from 1592 to 1593, which records that the town paid the Shakespeare Company to come and play at the venue,” explains Tim Fitzhigham, the Guildhall's creative director.

The floorboards were unveiled last month during a renovation project at the Guildhall. It has been covered for 75 years after a replacement floor was installed in the theatre.

Dr. Jonathan Clark, an expert on historic buildings, was brought on board to research the place. “We wanted to open up an area just to check, just to see if there was a previous floor still standing here. And lo and behold, we found this,” he says, pointing through a makeshift trapdoor.

A few inches below the modern floor are what are believed to be cold tread boards, each 12 inches (30 cm) wide and 6 inches deep.

Dr Clarke used a combination of tree-ring dating and a survey of how the building was assembled (“really unusual in that the panels were locked together and then joined by some massive bridge beams”) to date the grounds to between 1417 and 1430, when the Guildhall was originally built.

“We know that those [floorboards] “They were definitely here in 1592, and in 1592 we think Shakespeare is performing at King's Lynn, so that's probably the surface that Shakespeare was walking on,” he says.

“It is the end of the hall where the performances were held.”

Dr Clarke believes this is a very important discovery because it is not only the largest 15th century wooden floor in the country, but it will also be the only surviving example of a theater in which Shakespeare acted.

“It's the only upstairs, that was in more or less original condition, where he could have walked, or he could have performed,” he says.

Tiffany Stern, professor of Shakespeare and early modern drama at the University of Birmingham, told the BBC: “The evidence that he was there has to be tinkered with but is very strong.”

She says it is “very likely” that he was a member of the Earl of Pembroke's men because they staged his plays Henry VI and Titus Andronicus, and visited King's Lynn in 1593.

“Uncovering the actual slabs trodden on by Shakespeare's company during their tours of East Anglia should be of more interest to Elizabethan theater archaeologists than speculative speculation,” says Michael Dobson, director of the Shakespeare Institute in Stratford-upon-Avon. A replica of the Globe Theater built near the foundations of the real, long-demolished Globe in central London in the 1990s.

Returning to the setting, Fitzhigham believes a number of theories strengthen the argument Shakespeare made there.

He points out that Shakespeare's comedian Robert Armin was born just a street away, while a Norfolk writer called Robert Greene described the poet as “an arrogant crow” in what was essentially a bad review in 1592.

The debate will continue. On Thursday, this discovery will be discussed in a lecture in a place called “Guild Hall Secrets Revealed.”

Finally, Fitzhigham takes me downstage, has us squeeze between the beams and use a torch, to allow a closer look at the huge expanse of medieval floorboards, which he explains is the size of a tennis court.

“600 years,” he says with a real sense of amazement.

“It's not just Shakespeare that's been trampled on, but everyone in between, and we're trying to make that safe and share it with everyone for hundreds of years from now on.”