A theatre in Norfolk believes it has uncovered a 600-year-old doorway that may have once been the entrance to William Shakespeare’s dressing room.

St George’s Guildhall in King’s Lynn made the discovery during recent archaeological investigations, sparked by a strange shape in a ground-floor wall.

Specialists worked to remove the plaster and 18th-century brickwork, revealing a much earlier archway believed to have been built before 1405.

The top of the 15th-century archway uncovered behind a wall at St George's GuildhallThe top of the 15th-century archway was uncovered behind a wall at St George's Guildhall (Image: St George's Guildhall/PA Wire) Further exploratory work identified the arch as the door to what is believed to be the Guild Robing Room.

“This is another mind-boggling discovery at the Guildhall,” said Mr FitzHigham, creative director of St George’s Guildhall.

READ MORE: New excavations to shed new light on remarkable Norfolk archaeological site

“We’ve got a door that would definitely have been here in the years we think Shakespeare played here and, in all likelihood, was the door to a room where the players changed and stored props.

“It is simply staggering that again a slight hunch or weird shape in the wall has turned out to be something frankly extraordinary.”

Medieval oak boards that were uncovered in the theatreMedieval oak boards that were uncovered in the theatre (Image: St George's Guildhall/ PA Wire) The latest discovery comes after the theatre - the oldest working theatre in the UK - previously identified floorboards believed to have been part of a stage once trodden by the playwright. 

The theatre’s first recorded performances were in 1445, before the birth of Shakespeare – who was baptised in 1564 and died in 1616.

In Shakespeare’s time, St George’s Guildhall was used extensively by touring companies and Queen Elizabeth’s Men, a troupe of actors formed in 1583, performed there 10 times in the late 1500s.

ShakespeareShakespeare is believed to have performed at the theatre (Image: Archant) In 1592 and 1593 London’s theatres were closed due to an outbreak of plague and Shakespeare and his company of actors went on tour in King’s Lynn.

The theatre is currently being restored with government funding from King's Lynn's £25m town deal.