England's enigmatic Stonehenge served as a burial ground from its earliest beginnings — perhaps for ancient kings or chieftains, researchers reported Thursday.
Radiocarbon dating of cremated remains shows that burials took place as early as 3000 B.C., when the first ditches around the monument were being built, said University of Sheffield archaeologist Mike Parker Pearson. Those burials continued for at least 500 years, when the giant stones that mark the mysterious circle were being erected, he said.
Parker Pearson heads the Stonehenge Riverside Archaeological Project, which has been excavating sites around the world-famous monument for five years. He said the burial patterns support the idea that Stonehenge served as England's grandest Neolithic family cemetery.
"We're wondering if we're looking at the burial ground of an ancient royal dynasty," he told reporters.
He emphasized that Stonehenge was not exclusively a cemetery: The stone circle's orientation, which points to sunrises and sunsets on key seasonal dates, clearly shows it was a place of ceremony. And just last month, other researchers speculated that Stonehenge may have been an ancient place of healing as well.
Parker Pearson wouldn't rule out what he called the "healing hypothesis," but he said the idea that Stonehenge started out as a burial ground — and was used for that purpose for centuries — was on much firmer archaeological ground.
"It's important to remember that these kinds of stone monuments may well have had multiple meanings and understandings by the people themselves," he told msnbc.com. "Healing may have been a part of it, but I suspect that it's a very small part."
The project is supported by the National Geographic Society, which discusses Stonehenge in its June magazine and will feature the new burial data on "Stonehenge Decoded," a TV documentary premiering Sunday on the National Geographic Channel.
In the past many archaeologists had thought that burials at Stonehenge continued for only about a century — from roughly 2700 to 2600 B.C.
However, Parker Pearson and his colleagues found evidence of earlier cremation burials, by looking at remains excavated in the 1950s and kept at the nearby Salisbury Museum. The remains were radiocarbon-dated for the first time, using a procedure that focuses on minerals left behind after cremation.
"It's only in the last five years or so that it's been possible to radiocarbon-date cremated bone," Parker Pearson explained.
One set of burned bones and teeth was recovered from pits ringing Stonehenge's circular ditch, known as the Aubrey Holes. Those bone fragments were dated to 3030-2880 B.C., just about the time that the first ditch-and-bank monument was being built at Stonehenge.
Remains from the surrounding ditch included an adult dated to 2930-2870 B.C., and the most recent cremation, Parker Pearson said, comes from the ditch's northern side and was of a 25-year-old woman. It dated to 2570-2340 B.C., around the time the first arrangements of large sarsen stones appeared at Stonehenge.
"The cremation burial dating to Stonehenge's sarsen stones phase is likely just one of many from this later period of the monument's use and demonstrates that it was still very much a domain of the dead,'' Parker Pearson said.
A royal dynasty?
Based on past excavations, Parker Pearson's team estimates that the cremated remains of 150 to 240 people were buried within Stonehenge over a 500-year period. As time went on, the pace of the burials apparently increased.
That would be consistent with a pattern in which a handful of members of an elite family are buried in the early years, and then more and more descendants are buried in subsequent centuries.
The timing of the burials is one line of evidence suggesting that Stonehenge served as a cemetery for a royal dynasty, Parker Pearson said. Another line of evidence is suggested by the discovery of a stone mace within one of the Stonehenge graves. The mace was seen as a symbol of authority in ancient times, just as it is today, Parker Pearson said.
"I don't think it was the common people getting buried at Stonehenge — it was clearly a special place at that time," he said. "One has to assume anyone buried there had some good credentials.''
The village of Stonehenge's builders
The archaeological project has also yielded new findings about Durrington Walls, the site of an ancient village that researchers believe housed Stonehenge's builders. Excavations of several houses at the site have led Parker Pearson and his colleagues to conclude that the village ranked as one of the biggest settlements of its time in northern Europe, with 300 to 1,000 houses.
Other evidence suggests that the village was occupied only on a seasonal basis, most likely at the time of ceremonial gatherings in midsummer and midwinter. For example, animal remains indicate that pigs were culled in the village, but not born there. That would be the case if people journeyed to the site only at certain times of the year, accompanied by their animals.
There are ample signs that a wooden version of Stonehenge, nicknamed Woodhenge, existed next to Durrington Walls in Neolithic times — and that a nearly 2-mile-long ditched enclosure ran across the plain between the monuments. The project's archaeologists excavated a wooden "Southern Circle" inside Durrington Walls' circular ditches that appears to be oriented toward the midwinter sunrise, contrasting with Stonehenge's orientation toward the midsummer sunrise and the midwinter sunset.
The project's archaeologists speculate that the area around Durrington Walls served as the "domain of the living," and that Stonehenge represented "the domain of the ancestors." Bodies of the dead may have been transported down an avenue leading from the village to the River Avon, then brought to Stonehenge.
Such a journey would symbolize the transition from life to death — "crossing the River Styx, as it were," Parker Pearson said.
He said the archaeological digs, which are due to continue this summer, are providing "intimate portraits, really, of how people lived their lives." One excavation of a house at the Durrington Walls village even turned up what appear to be two worn spots in the floor near the hearth. "Whoever was in charge of the housework and the cooking was kneeling there," Parker Pearson said.
The mystery in the parking lot
Many more mysteries have yet to be addressed: For example, the archaeologists say two oval-fenced areas along the clifftop south of Woodhenge enclosed monumental timber structures, each anchored by four large posts.
"These obviously were not domestic buildings," University of Bristol archaeologist Joshua Pollard said in a statement. "Their purpose is uncertain, but it's possible they supported raised platforms where bodies of the dead were left to decay."
Then there's the mystery over why Stonehenge was selected as a sacred site in the first place. Parker Pearson said three pits that are marked today by concrete circles in Stonehenge's parking lot once held huge posts or pine tree trunks. Those pits date back 10,000 years, he said.
"They were built 5,000 years before Stonehenge was begun," Parker Pearson said. Thus, now-vanished monuments may have existed at the site millennia before Stonehenge was even conceived.
"We either have a very long-term tradition ... or maybe they get rediscovered and reckoned to be the footprints of the ancestors," Parker Pearson said.
This report includes information from Randolph E. Schmid of The Associated Press and Alan Boyle of msnbc.com.