The find is described as one of the most significant for decades.
A team of historical experts from the Museum of London carried out excavations in connection with the Priory Crescent road widening scheme. The museum described the find as "spectacular and amazing" and dubbed the king Prince of Prittlewell.
Now campaigners against the road widening hope the find could halt the scheme.
SOUTHEND'S controversial Priory Crescent road widening scheme could be scrapped after an archaeological discovery of international importance.
An Anglo-Saxon king's burial chamber was found alongside the road, which Southend Council wants to widen by building a dual carriageway.
Protesters have attacked the scheme, claiming it would cause major damage to Priory Park itself and mean the loss of 137 trees.
Today opponents of the scheme were celebrating what they believe will be the final nail in the coffin of the proposals.
Chris Keene, Green Party campaigns co-ordinator for England and Wales, who lives on Canvey, said: "We have always said it was a major place of environmental importance. Surely this will be the final nail in the coffin for a ridiculous scheme."
Shaun Qureshi, a Greenpeace spokesman, who has led the campaign against the widening, added: "This exceeds our wildest expectations. I wonder what will happen next.
"Will the burial site have to be removed or will it be protected? If it is protected, surely the council could not carry on with the road scheme.
"Maybe it will take a discovery like this to prove the undoing of the road widening."
The campaign to stop the dualling of Priory Crescent has been going on for more than three years.
The scheme has been held back until a public inquiry, due to start in early March, has been undertaken into compulsory purchase orders for the plan.
Mr Qureshi added: "This is our park and the people of Southend feel very strongly about it.
"Not an inch of that park should be taken.
"It is a peaceful place, but that peace would be lost if a dual carriageway was put in."
Green Party spokeswoman Irene Willis said: "Perhaps history has come to save Priory Crescent."
A council spokeswoman said further investigations would have to be carried out before a decision on the future of the road scheme could be made. Asked whether any finds would be likely to halt the scheme, she said: "This cannot be determined until the archaeological report is received.
"But all mitigation options will be considered alongside an archaeological solution, and or an engineering solution, to safeguard any finds."
THE discovery of a seventh-century king's tomb beneath Southend was today described as the most important archaeological find in western Europe in living memory.
Historian David Keys, who has made an in-depth study of that period in the country's history, said: "As soon as this gets out to the archeological community, people will be absolutely gobsmacked. This find was completely unexpected.
"It truly is of international importance."
The big question is the identity of the king. Two names being talked about are Saeberht and Sigeberht, Saxon kings of Essex who lived at a pivotal moment in this country's history.
Mr Keys, author of Catastrophe - An Investigation into the Origins of the Modern World, said: "Christianity was being adopted in the lands ruled by the Jutes, Saxons and Angles.
"These were virtually tribal cultures where the kings were viewed as a the first among equals, and little more.
"With the acceptance of Christianity, the kings came to be perceived as somebody put there by God."
The location of the discovery is well-known for Anglo-Saxon remains. The name Prittlewell derives from the Germanic dialect, meaning "bubbling spring". Previous local finds included the graves of Saxon warriors and noble women.
Saeberht was the nephew of Ethelbert, King of Kent. He followed in his uncle's acceptance of the new religion, though his children reverted to paganism.
With Sigeberht, Christianity was restored.
His reight was cut short in 653, when he was murdered by a group of his own lords, apparently for being too lenient with his enemies.
THE "spectacular, amazing" burial site of an Anglo-Saxon king in the heart of Southend has been hailed by historians as a once in a lifetime discovery.
The site contains incredible objects that are providing a fascinating glimpse into the life anddeath of the super-rich of the Dark Ages.
Ian Blair, Senior archaeologist on the site, said: "To find an intact chamber grave and a moment genuinely frozen in time is a once in a lifetime discovery.
"Copper-alloy bowls were still hanging from hools in the walls of the chamber, where they had been placed nearly 1,400 years ago, which is a memory, I'm sure, which will remain with all of us forever."
The wood-lined chamber, hung with a lavish collection of treasures, is probably contemporary with the Sutton Hoo ship burial unearthed in 1939, during which a pagan king was found.
It is possible the pagan king and the East Saxon king found in Southend knew each other.
Two gold foil crosses suggest this king was a newly converted Christian, but he was also taking with him everything he might need to carry on his glamorous life.
Some of the treasures are imported from the farthest corners of the world and many have survived in remarkably good condition. They include wooden vessels with exquisitely decorated gilded mounts, a gold buckle and traces of gold braid, as well as coloured glass vessels and copper bowls.
The find is spectacular in its size and quality, but what makes it unique is that all the objects were in their original positions, just as they had been arranged on the day of the funeral.
The most exotic finds are a decorated flag and at least one bowl imported from the eastern Mediterranean, possibly Asia Minor.
Other highlights among the 60 or more finds are a hanging bowl decorated with metallic strips and medallions, and two cauldrons, one small and one vast, measuring 75cm across.
There are also eight wooden drinking cups degorated with gilded mounts, buckets and the remains of a large casket that may have originally contained textiles.
The dead man had also been provided with two Merovingian gold coins from northern France, a sword and a shield.
The contents of the tomb had been held in place because sand from the mound sealing the grave gradually seeped into the chamber, silting up the air spaces and supporting the roof-timbers.