Ireland's links with the Roman empire are being investigated in a new archaeological project in which science plays a large part writes ANTHONY KING

FIRST CENTURY AD. The Roman General Agricola reportedly says he can take and hold Ireland with a single legion. Some archaeologists have claimed the Romans did campaign in Ireland, but most see no evidence for an invasion. Imperial Rome and this island on its far western perimeter did share interesting links, however.

The Discovery Programme, a Dublin-based public institution for advanced research in archaeology, is to investigate Ireland’s interactions with the empire and with Roman Britain, aiming to fill gaps in the story of the Irish iron age, the first 500 years after the birth of Christ.

The project, Late Iron Age and Roman Ireland (Liari) could uncover a surprising role for Roman culture, predicts Dr Jacqueline Cahill Wilson, project leader. It offers “a new narrative for this formative period of early Irish history”.

Science is going to drive the project, and the interpretation presented by the researchers will be based on science as much as the archaeology, Cahill Wilson explains.

Roman artifacts including coins, glass beads and brooches turn up in many Irish counties, especially in the east.

Cahill Wilson investigated human remains from iron age burial sites in Meath for her doctoral research at the University of Bristol. She learned much about these people by using strontium and isotope analysis and carbon dating.

Remarkably, this allowed her say where they most likely spent their childhood. One burial site on a low ridge overlooking the sea in Bettystown, Co Meath, was dated to the 5th/6th century AD using radiocarbon dating. Most of the people were newcomers to the area, Cahill Wilson concluded.

The clue was in their teeth. Enamel, one of the toughest substances in our body, completely mineralises around the age of 12 and its composition remains unaltered to the grave and beyond. It is “a snapshot of where you lived up to the age of 12”, Wilson explains.

The element strontium (Sr), which is in everything we eat and drink, exists in a number of chemical forms, or isotopes. The ratio of two of these isotopes (87Sr and 86Sr) varies, shifting with the underlying geology, and this too can indicate where the owner of the tooth grew up.

Similarly, the ratio of oxygen isotopes varies with factors such as latitude, topography and hydrological conditions.

“Enough comparative data is available now that we can start to plot and map the ratios to see where people are likely to be from,” Cahill Wilson explains. Paired analysis of strontium and oxygen in tooth enamel from a burial in Bettystown revealed that one interred individual grew up in North Africa.

Eamonn Kelly, keeper of Irish Antiquities at the National Museum of Ireland, distinctly remembers the Bettystown excavation, which he directed in the 1970s. “One particular burial stood out as being very unusual,” he says. The body lay in a crouched position and seemed to have been treated in a different manner to the rest of the burials. This male could have been a slave, but Kelly thinks he was most likely a trader, possibly from the Roman world.

Roman material has been found at Tara and Newgrange, and Roman pottery has been dredged from the River Boyne. A large coastal promontory fort in north Dublin also turned up Roman objects, and Kilkenny hosts a Roman burial site.

Kelly believes the Romans never invaded because the countryside was unsuited to their villa system: the economic cost-benefits failed to stack up, he says. “These guys could get what they wanted without being physically present. I think what they were interested in from Ireland was agricultural produce, probably butter, cattle and cattle hide, as well as slaves and mercenaries.”

The Liari project will deploy advanced survey techniques in Dublin, Westmeath and Kilkenny to seek evidence for Roman sites. Robert Shaw, senior surveyor for the programme, describes aerial laser scanning, or Lidar, as one of the most important developments in archaeology over the last 10 years.

This models the landscape surface in exquisite detail. The ground-based techniques rely on measurements of magnetic and electrical resistance anomalies of the earth, so no destructive digging is required.

Surveys are not expected to uncover the Roman’s distinctive linear roads or their large rectangular forts, but what did it mean to be “Roman” in Ireland?

The warring centurians and toga-wearing politicians made popular in film comprised less than two per cent of Roman Britain.

“The rest of the people engaged with the new Roman administration in a variety of ways,” says Cahill Wilson, and “there were different ways to be a Roman within the provinces”.

The project will use the latest scientific methods, such as geochemistry, to explore population migration, X-ray fluorescence and isotope analysis to trace the origin of metals and minerals, and pollen analysis to resurrect past environments.

“We need to be a bit more systematic and scientific in terms of what we are doing,” says Cahill Wilson, but these tools are additions to traditional archaeology’s kit.

Kelly says it is not surprising Roman material turns up, especially on the coast facing Roman Britain. We know Niall of the Nine Hostages had a British mother, he says. “These guys were marrying women from the other side of the Irish Sea. There would have been dynastical alliances across the sea.

“Ireland was in immediate proximity to the world superpower,” he adds. “Ireland was becoming heavily influenced from the 1st century AD by Rome. The introduction of Christianity in the 5th century is just part of that process.

“We took on a great swathe of Roman cultural influence, including the Roman religion, and all without a Roman legion landing and telling us how to do our business.”

At the National Museum, Kildare Street, Dublin, visitors can see displays of imported Roman objects and the influence of the Roman world on the culture of pagan and early Christian Ireland in the Treasury exhibition. A second exhibition hosts objects from across the Roman world

Bodies in the bog: uncovering the rituals of death

"WE HAVE A national anatomical collection second to none," says Eamonn Kelly, Keeper of Irish Antiquities at the National Museum of Ireland. He is referring to the thousands of human remains held in a custom-built store.

These are hugely important to archaeological and medical research, but the meticulous archives on the excavations are also a treasure trove, says Kelly.

Remains still turn up. An Iron Age body found in a Laois bog last August is giving up its secrets under scientific scrutiny. The remains are in the process of being dated using radiocarbon methods and a forensic examination has been carried out to identify injuries. This bog body, believed to be a ritual sacrifice, underwent a CT scan out-of-hours in Tallaght Hospital last December. Museum staff will now be looking to see if the remains of a ritual meal are still present in the body.

Laureen Buckley is an experienced forensic archaeologist, often called to crime scenes. But she examines mostly prehistoric remains. "When they come into the lab, they are cleaned up and laid out on a table, similar to a post-mortem. Everything is laid out in its correct place and you go through it bone by bone."

She can sex skeletons by examining the shape of the bones in the skull, the pelvis and ribs. "There are features of the skull, the supra-orbital ridges in the forehead and the mastoid process behind the ear. These are fairly well developed and pronounced in males, but softer and smaller in females."

Aging can be done up to about 25 years, after which all bones are fully mature. Gauging age after that becomes more difficult, says Buckley.

Prehistoric can be distinguished from modern and medieval remains by looking at the teeth. A softer modern diet causes less wear on teeth.

Another novel way to identify a post-medieval, but not modern, individual is by notches on their teeth. These little semi-circles are the vestiges of hours spent smoking tobacco with a clay pipe. Tobacco was introduced in the 17th century and clay pipes went out of fashion by last century.

A new book to be published shortly will document more than 400 burial sites over a 70-year period by museum archaeologists - Breaking Ground, Finding Graves.