Nan Madol tomb
A tomb in Nan Madol gallenm../Flickr

The monumental tomb of the first ever chief of Nana Madol on the Pacific island of Pohnpei is helping shed light on how other, more ancient societies form. New techniques have allowed scientists to accurately date the tomb of the first Saudeleur – the point at which the society went from being a series of groups to an island united under one ruler.

Nana Madol was the capital of the Saudeleur Dynasty of Pohnpei until the 1620s. It is now the largest archaeological site in Micronesia. The island – an inactive volcano – is about the size of Columbia at 128sq/m. It was originally settled on by people from Solomon or Vanuatu in the first century AD. Oral history indicates the Saudeleur Dynasty first emerged around 1160, but physical evidence for this has been lacking.

In a study published in Quaternary Research, a team led by Mark D McCoy, of the Southern Methodist University in Dallas, has shown exactly when the first tomb in Nana Madol was built. By knowing this, they were then able to infer when the first chief of Pohnpei emerged.

The tomb studies is the largest and most elaborate example of architecture in Nana Madol. It measures 80m x 60m and is over eight metres tall. Its exterior walls are three metres thick in places. Inside is a maze of walls, leading to a crypt. "The architecture is meant to be extremely impressive, and it is," McCoy said. "The structures were built to last — this is one of the rainiest places on earth, so it can be muddy and slippery and wet, but these islets on the coral reef are very stable."

Pohnpei Nan Madol
X-ray gun was used to date the stones. Mark McCoy

The scientists used an X-ray gun to geochemically match the massive basalt stones the tomb is built from to natural sources on the island. They also used uranium dating on the coral on which the tomb was built. Their findings showed the tomb was built between 1180 and 1200 AD. This pushes back the dating of Nan Madol by 100 years, with previous dating showing its establishment in 1300 AD.

Engineering mystery

How the tomb was built is not known. The islanders would have had to transport these massive stones from the opposite side of the island. McCoy said the tomb is comparable to Egypt's pyramids: "The construction, like the Pyramids, didn't help anyone — it didn't help society be fairer, or to grow crops or to provide any social good. It's just a really big place to put a dead person," McCoy said.

But the creation of a huge tomb for the first ruler has important implications as it could help shed light on how other, far more ancient societies emerged and developed a system that one ruler presided over.

"At A.D. 1200 there are universities in Europe. The Romans had come and gone. The Egyptians had come and gone. But when you're looking at Pohnpei, it's very recent, so we still have the oral histories of the descendants of the people who built Nan Madol. There's evidence that you just don't have elsewhere," McCoy said.

Pohnpei Luigi Guarino/Flickr

"The kind of society that we live in today ... has its roots in a pre-modern era like Nan Madol where you have a king or chief. These islanders invented a new kind of society — that is a socially creative achievement. The idea of chiefs, someone in charge, is not a new thing, but it's an extremely important precursor. We know tribes and bands predate chiefdoms and states. But it's not a straight line. By looking at these intermediate stages we get insight into that social phenomenon.

"The thing that makes this case special is Nan Madol happened in isolation, it happened very recently, and we have multiple lines of evidence, including oral histories to support the analysis. And because it's an island we can be much more specific about the natural resources, the population – all the things that are more difficult when people are on a continent and all connected. So we can understand it with a lot more precision."