The discovery of a ship lost off the coast of Great Yarmouth 340 years ago has been hailed as the most significant maritime find since the raising of the Mary Rose.

The Gloucester was heading to Edinburgh carrying a future king of England and an array of nobles when it collided with a sandbank 45km off Great Yarmouth on May 6, 1682, sinking within an hour.

And because the ship sank so quickly nothing was saved, offering the tantalising prospect of chests full of personal and royal items waiting to be explored.

Up to 250 people died in the tragedy, but crucially James Stuart the Duke of York - later James II - was saved, changing the course of British history.

Artefacts recovered so far include clothes, shoes, and unopened wine bottles, providing a rich time capsule of life on board a 17th century ship and firing imaginations across the world.

The ship itself, the most famous warship of its day, is half buried in sand and there are currently no plans to raise it.

It was found in 2007 by Norfolk divers Julian and Lincoln Barnwell, with their friend James Little, after a four-year search covering 5,000 nautical miles.

The long process of identifying it by its cannon as well as issues around site security mean the discovery is only now being made public.

Prof Claire Jowitt, a world-leading authority on maritime cultural history at the UEA, said: “Because of the circumstances of its sinking, this can be claimed as the single most significant historic maritime discovery since the raising of the Mary Rose in 1982.

"The discovery promises to fundamentally change understanding of 17th-century social, maritime and political history.

“It is an outstanding example of underwater cultural heritage of national and international importance.

"A tragedy of considerable proportions in terms of loss of life, both privileged and ordinary, the full story of the Gloucester's last voyage and the impact of its aftermath needs re-telling, including its cultural and political importance, and legacy.

"We will also try to establish who else died and tell their stories, as the identities of a fraction of the victims are currently known.”

No human remains have been found. The Duke's quarters in the stern are buried and could yet yield treasures.

Lincoln Barnwell said he was partly inspired to search for the wreck after watching the lifting of the Mary Rose on television as a child.

“It was our fourth dive season looking for Gloucester,” he said.

“We were starting to believe that we were not going to find her, we’d dived so much and just found sand.

"On my descent to the seabed the first thing I spotted were large cannon laying on white sand, it was awe-inspiring and really beautiful.

“It instantly felt like a privilege to be there, it was so exciting.

"We were the only people in the world at that moment in time who knew where the wreck lay. That was special and I’ll never forget it.

"Our next job was to identify the site as the Gloucester.”

Julian Barnwell added: “When we decided to search for the Gloucester we had no idea how significant she was in history.

"We had read that the Duke of York was onboard but that was it.

"We were confident it was the Gloucester, but there are other wreck sites out there with cannons, so it still needed to be confirmed.

“There is still a huge amount of knowledge to be gained from the wreck, which will benefit Norfolk and the nation.

"We hope this discovery and the stories that are uncovered will inform and inspire future generations.”

Researchers at the UEA will continue to analyse finds ahead of a major exhibition planned for Spring 2023 bringing the story to life.

The Last Voyage of the Gloucester: Norfolk’s Royal Shipwreck, will be jointly curated by UEA and Norfolk Museums Service and staged for five months at Norwich Castle Museum and Art Gallery.

Lord Dannatt, Norfolk Deputy Lieutenant, is supporting the historic rescue project.

“This is going to be Norfolk’s Mary Rose,” he said.

“Julian and Lincoln have touched history, history that could have changed the course of this nation. It’s such an amazing story to tell. Our aim is to bring that story to life and to share it with as many people as possible.”

Ship's timeline

1654 - The Gloucester is launched after being built at a private dockyard in Limehouse as a republican war ship.

1654-60 - Takes part in multiple battles during the Anglo-Spanish war.

1660 - Taken over by the Royal Navy after the restoration of the monarchy.

1665 - 1673 - Takes part in multiple battles in the second and third Anglo-Dutch Wars, such as the Battle of Lowestoft (1665) and Battle of Sole Bay (1672).

1682 - Wrecked on a sandbar while carrying the Duke of York, the future James II.

2007 - Brothers Julian and Lincoln Barnwell pinpoint the wreck site after four years of searching.

2012 - One of the rescued finds, the ship’s bell, is used to conclusively confirm the wreck is the Gloucester.

2022 - Discovery made public and hailed as 'Norfolk's Mary Rose'.

Who was the King James II?

James Stuart, the Duke of York, came to the throne in 1685 on the death of his brother Charles II. He was England's last Catholic king and was deposed by the Glorious Revolution less than four years later.

His reign is remembered mainly for struggles over religious tolerance and over the principles of the divine right of kings.

His role in the Gloucester saga contributed to his downfall in that it was sailing to his course, against the advice of others, making him responsible for the tragedy, some said.

His detractors also claimed he saved his dogs and Catholic priests at the expense of the lives of his courtiers and the ship's crew, and blamed the pilot who was imprisoned.

If James had drowned in 1682, Charles II’s illegitimate son, James Scott, the Duke of Monmouth, may have come to the throne.

In that case the 1688 revolution, which deposed James and created a new type of state giving parliament the upper hand, would not have happened.

He died aged 67 in exile in France.