Broxmouth was excavated shortly before the site was destroyed by a cement works.
The community lasted for almost 1,000 years before the area was abandoned when the Romans left. The research is published in the latest edition of the magazine British Archaeology.
Professor Ian Armit from the University of Bradford, who led the team investigating the site, said: “What we found has turned round preconceptions of the site. We’ve got a level of detail that would never have been possible before, because of the very large number of high quality radio carbon dates.”
He said there was some evidence of activity at Broxmouth as long ago as 3000 BC. But the story really begins around 600 BC. At that time a wooden stockade was constructed round the hilltop. But each generation built over what was there before it, so it was only the remains that were left by accident that allowed his team to work out the different stages of construction.
Next came a monumental timber roundhouse, and its auxiliary structures, then a hill fort was built at the site.
The archaeologists also uncovered a cemetery at the site, containing a tiny proportion of the residents who must have lived there.
Some of the graves were very elaborate, perhaps suggesting that they contained the remains of high status individuals but there were also fragments of bones from people who died violent deaths, from sword or axe wounds.
“It looks like they were outsiders either killed at the site or remains brought back there as human trophies”, Professor Armit said.
“That suggests either feuding or raiding but we can’t say if they came from twenty miles away, or from 200 miles away.”
He said the most striking finding was that the site was home to a very settled and stable community, which lasted until about 200 AD.
That “seems to have coincided with the period when the Romans withdrew,” Professor Armit explained.
“It looks as though the people of East Lothian may have been allied with the Romans as there are no Roman military installations in the area.”