A 2,500-year-old settlement discovered during work on a housing development is said to be of international significance and is enabling the largest study of an Iron Age population in the last 35 years.
The site in Pocklington, East Yorkshire, includes more than 75 square barrows that contained skeletons from the Arras Culture - a group of people who lived in the region in the Middle Iron Age as far back as 800BC.
The excavation at the site - a development by David Wilson Homes - has already revealed objects including a sword, shield and 10 spears.
In addition to the weapons, more than 360 amber and glass beads, brooches and ancient pots have also been discovered.
A spokesman for the developers said the site is of "national and international significance".
He said the analysis will hopefully also reveal how those buried at the site died, what stresses the body had been placed in during their lifespan and whether or not they are related.
A major focus area of the archaeological analysis will concentrate on whether the population is indigenous or migrants from the continent, he said.
The spokesman said the majority of barrows excavated have been well-preserved, with only a few being damaged by soil conditions and ploughing. The findings also reveal a mixture of men, women and children.
Paula Ware, managing director at MAP Archaeological Practice, said: "To date, the east of Yorkshire has the largest concentration of 'Arras Culture' square barrows, and naturally these findings have helped to strengthen this.
"We are hoping that these findings shed light on the ritual of Iron Age burial - and, as we can assume from the shield and sword burials, these were significant members of society, so our understanding of culture and key figures of the time could be really enhanced.
"On the whole this is a hugely important discovery and is a fine example of what can be revealed and discovered if house developers and archaeologists work hand-in-hand to reveal the nation's hidden history."
David Wilson Homes found the settlement at its Pavilion Square development after it started work in September 2014. The discovery will be officially announced on BBC Four's Digging for Britain at 8pm on Thursday.
Peter Morris, development director at David Wilson Homes, said: "These findings are of national significance and could help shape our understanding of the 'Arras Culture' and indeed the Iron Age as a whole.
"At present we are still at the early analytical stages of reviewing these findings, however we do understand that this discovery is very rare and of international importance."