The shipwreck has lain in the Thames Estuary for 350 years

A rare and well-preserved 350-year-old gun carriage - described as a national treasure - has been raised from the depths from a 17th century shipwreck.

The wooden carriage remains in almost pristine condition after being buried in silt since the warship the London accidentally exploded and sunk in the Thames Estuary in 1665.

The carriage has lain undisturbed until now when concerns it was beginning to deteriorate prompted Historic England to step in.

Working with a team of amateur divers from Leigh-on-Sea, Essex, it was lifted from the seabed yesterday and returned to shore today.

Historic England archaeologist Alison James said: "This is a hugely significant wreck - the London is the only ship of its kind surviving on the seabed.

"It really is a time capsule which can provide us with so many insights.

"Now it has been lifted we can begin to look at how the carriage was made.

"It is a great relief to have successfully lifted it. Archaeology can be a destructive process as you are taking artefacts out of their natural environment, so it is great to see it safely on shore."

The waterlogged wooden gun carriage is estimated to weigh one tonne and is 5ft 2in (1.6 metres) long and 2.3ft (0.7m) wide.

It was discovered about 60ft (18 metres) below the surface by a team of divers led by husband and wife Steven and Carol Ellis, from Leigh, last summer.

Over the past eight months, parts of the carriage became exposed, placing it at risk of breaking up due to the strong currents and exposure to sea worms.

It was lifted using a 20-tonne crane barge with divers on hand to ensure the fragile wood was protected and did not dry out.

Mr Ellis said: "I have been one of only a privileged few who was able to see the London on the seabed.

"This area isn't often dived because of the tides and the silt, which means it is often pitch black below the surface.

"We knew the London was there but, because it was protected, we weren't allowed to dive it until recently.

"We began working with Historic England and mapped the site.

"Some of the personal artefacts we have found have been outstanding. I brought up a 350-year-old leather show which was still as it would have been the day it was made.

"We also found a perfectly preserved pocket sundial."

He said conditions had been tough for the lifting operation but he was glad it had been completely successful.

"It's really exciting that other people will now be able to see and experience it - why should we be the only ones?" Mr Ellis added.

The London was built between 1654 and 1656 at a time of political upheaval during the English Civil War and the first Anglo-Dutch War.

She was one of only three completed Second Rate warships and the only one that survives.

The ship was a former part of an English convoy sent in 1660 to collect Charles II from the Netherlands and restore him to the throne in an effort to end the anarchy which followed the death of Oliver Cromwell in 1658.

But she sunk on March 7 1665 in an accidental explosion.

Neil Holbrook, chief executive of Cotswold Archaeology, which provided technical expertise for the lift, described the operation as a career highlight.

He said: "How often do you get the chance to take something from the seabed in almost pristine condition?

"We couldn't have done it without the local divers. They helped catalogue every item so we have the context of how they were found, which can teach us a great deal."

The carriage will be taken to York to be preserved before going on public display at Southend Museum.