Dealing with time periods that trace back thousands and hundreds of thousands of years can be difficult to handle because of the range of dating systems used such as BC, AD, CE etc. For this blog dates will be recorded as BP – before present. This is to avoid conflicting terminology and confusion.
Simplistic timelines for early Irish human occupation up to the historic period are:
Mesolithic (Hunter Gatherers) 10,000 – 6,000 Before Present
Neolithic (Farming) 6,000 – 4,500 BP
Copper and Bronze Age 4,500 – 2,500 BP
Iron Age 2,500 BP – 400 AD
What mechanisms are there for identifying dates that trace back into the distant past? A number of research mechanisms are used. Firstly, land base studies include Greenland ice analysis, then lake sediment analysis and lastly radiocarbon dating. Newer research methods include undersea marine geological data which would include marine landforms and sediment cores. It is not possible to extract dates from stone tools/weapons unless there are associated artefacts that can be radiocarbon dated.
The Earliest Arrivals.
Long before homo sapiens emerged out of Africa dinosaurs roamed across the earth 200 – 145 million years ago. They roamed the European landscape and evidence of their existence can be found in nearly all European countries. Many examples have been found in Britain, mainly in the south. A Sauropod found in Dorset has been dated to 168 – 166 million years old.
During the 1980s four unusual bones were found along the Antrim coastline but were not recognised. They sat in boxes in the National Museum Northern Ireland until 2020 when they were re-examined in an attempt to identify them. Two of the bones were identified as dinosaurs but from two different species. One of them was the leg bone of a two-footed meat-eating Megalosaurus from 166 million years ago, while the second bone came from a four-footed, plant-eating Scelidosaurus from 191 million years ago. It is likely that these animals arrived in Ireland when Ireland and Europe were one land mass.
Megalosaurus and Scelidosaurus
Last Ice Age
The last Ice Age lasted from 27,000 – 15,000 BP. Most of northern Europe was covered in ice while southern Europe was turned into an artic tundra.
Ireland has been glaciated many times. As the ice spread south the impact on animals, plants and the people in Europe was significant, driving them southwards. In front of the ice the cold weather turned the environment into an artic tundra. This forced animals and humans to cope and change location in order to survive. The sea levels reduced as the ice caps increased. One estimate is that the sea levels were about 120m lower that at present.
It is still argued how much the ice sheets covered Ireland with some suggesting that some areas at some periods were ice free (those Kerry people again!). There is no consensus on how deep the ice was that covered Ireland, some suggest that it was 1 km deep. However, John Feehan has suggested it may have been 2 km deep.
A mini-ice age, called the Younger Dryas, arrived in Ireland some 12,800 years ago. It was a swift, intense cold period, taking about a decade to develop. The dates were identified from the mud deposits of an undisturbed Lough Monreagh in Co. Clare. This mini-ice age lasted around 1,300 years.
It is certain that glaciers formed on the top of Ireland’s mountains during this period. The climatic conditions had mean monthly low temperatures as low as -25o C, very cold winters with strong winds and unable to sustain human occupation. The oldest Irish pollen data was recorded at Tory Hill, Limerick and dated at 14,000 BP. The Irish lake sediments are dominated by non-tree pollen with herb and shrub dominating at this time. A 2013 paper listed a catalogue of Irish pollen analyses and shows that in Offaly 14 samples had been taken from raised bogs, 3 in lakes and 2 in woodland areas.
Ireland, Britain and Doggerland.
As the ice shield melted and moved northwards the sea levels in northern Europe were much lower. This resulted in a land mass that had Britain joined on to Europe, with animals and plant life flourishing and moving across Europe as the tundra disappeared.
Doggerland was a very large land mass that connected modern Denmark with the east coast of England, this stretched down to the Normandy region in France across to the Bristol Channel.
Map of Doggerland
Humans had not reached Ireland at this time. This mini-ice age drove fauna out of Ireland and Britain while the human population fled Britain back to Europe and headed south until about 12,000 BP. After this cold period Ireland became ecologically viable by 11,700 BP.
The return of humans northwards was slow with colonisation of the Hebrides arriving about 11,600 – 9,500 BP.
More Early arrivals.
The last mammoths roamed through Europe at the end of the last ice age after more than 100,000 years of surviving encroaching and retreating ice. The mammoth finally died out from the British Isles around 11,000 years ago. Only a few traces of mammoth remains have been found in Ireland.
Evidence of this is seen in the accidental discovery of the bones of a woolly mammoth and a musk ox when a lignite mine was being explored at Aghnadarragh, County Antrim in 1987. The bones were found under five layers of glacial deposits. Again, it is unclear how these animals arrived in Ireland. Teeth enamel is excellent for dating, these teeth provide a date of 95,000 BP.
Aghnadarragh Mammoth tusk Woolly Mammoth
Also discovered at the same dig at Aghnadarragh was the partial skull of a musk ox. This is the first, and to date the only record of this species in Ireland. Musk oxen still live in the frozen Arctic and roam the tundra in search of the roots, mosses, and lichens that sustain them. These animals have inhabited the Arctic for many thousands of years, and their long shaggy hair is well adapted to the frigid climate.
With the final melt of the Ice Age junipers arrive in Ireland, quickly followed by birch. Charcoal remains from wildfire activity show the arrival of willow and heaths indicating rapidly warming conditions.
What was left after the ice and left?
Ireland as an island was much larger and gradually reduced in size as the sea levels rose because of the melting ice cap. As the ice receded northwards plants and animals returned across Europe, the impact to the Irish midlands and, particularly Co Offaly was significant. The melted ice flowed into the bowl of the central plane, creating extensive lake and river systems. The early lake and river systems were connected initially, see Killian Driscoll’s (NUIG) map below. In his YouTube John Feehan suggests that the glacial impact on Offaly resulted in the Shannon being a series of large and small lakes. Because the earth surface had carried the weight of the tonnes of ice cover for thousands of years the land crust started to rise up again.
Post-glacial midland lakes
There is much evidence on how flooded the central Midlands were after the ice age. One of the more interesting deposits left behind were mushroom stones. The mushroom stone at Crancreagh, Co Offaly shows signs that the lake level reduced over two significant periods. Carving the stone into its unique mushroom shape was the result of waves lapping against it over two distinct periods.
One of the obvious leftovers from the ice age are our drumlins. Drumlins (from the Irish droimnín, or little hills) are hills of rock, sand and gravel that formed under the glacial ice. Just as the sea creates ripples on a sandy seashore, the ice sheet created these great ripples, or bedforms, which are up to 400 metres high in some places. The island of Ireland has over 20,000 drumlins.
Eskers are long, narrow winding ridges of dumped material comprised of boulders and clay found in lowland areas. Eskers formed when tunnels developed under an advancing ice sheet. The tunnel probably arose in response to the presence of an obstacle to the advancing ice which then burrowed the tunnel under the ice sheet. Tunnels may also have developed in response to meltwater flowing in crevasses in the glacier.
The Eiscir Riada runs from Kilmainham in Dublin to Clonmacnoise in Offaly today. The Eiscir Riada was one of the five main highways that miraculously arrived on the night that Conn Céadcathach was born. As the Annals of the Four Masters says ‘The first year of Conn Céadcathach of the Hundred Battles as king over Ireland. The night of Conn’s birth were discovered five principal roads leading to Teamhair, which were never observed till then. These are their names: Slighe Asail, Slighe Midhluachra, Slighe Cualann, Slighe Mor, Slighe Dala. Slighe Mor is that called Eiscir Riada, i.e. the division line of Ireland into two parts, between Conn and Eoghan Mor.’ (M123.1)
Europe and Britain.
Britain was occupied by humans after the last ice age around 14,600 BP and again about 12,000 BP after the Younger Dryas. At this time the rising seas had cut Ireland off from Britain. This is at least 3,000 years before the first humans arrived in Ireland. When separated from Britain, Ireland had a very different flora and fauna environment from Britain and the rest of Europe. However, Britain continued to be joined to Europe by Doggerland.
With Britain attached to Europe both plants, trees, animals large and small transferred easily between the two. This meant that when the first Europeans arrived in the south of Britain, they found an environment no different to that in Europe.
Human occupation of Britain started again about 14,600 BP. Migration into Britain was slow, mainly to the south and then across to Wales. These Hunter Gatherers left traces in two significant locations in England – at Creswell Crags, Derbyshire and Cheddar Gorge, Somerset. Both locations had gorges where animals could be driven into, captured and slaughtered. The Hunter Gatherers stayed in caves in both gorges, leaving behind tools and the first rock art from these islands. The gorge at Creswell Crags has since been flooded to provide electricity generation to the British network. Doggerland finally disappeared about 8,000 BP and the land bridge was cut.
Creswell Crags and Cheddar Gorge
The larger animals available in Britain and Europe never reached Ireland; these included red deer, roe deer, reindeer, elk, artic fox, saiga antelope, auroch, wild boar, mammoth and particularly horse. The Irish diet was variable and seasonal with a large number of marine components. Fish was abundant, with many of the very early sites having cod, eel, trout and salmon. What Ireland also had was the Irish Giant Deer, reindeer, brown bear, wolf, stoat and mountain hare. Anyone arriving in Ireland would have had to struggle with the limited Irish food supply, irrespective on whether they arrive from Britain or from the Atlantic coast communities.
Finally, Human Arrivals in Ireland
For many years it had been assumed that Mesolithic Hunter Gatherers presence in Ireland was limited to a few locations in the north east of the country leading to the assumption that these first arrivals had crossed over from Scotland.
There were many theories on how they had arrived, and how they survived in a post glacial environment. As the ice cap was still melting in northern Europe the sea journeys would have been much shorter.
The first arrivals in Ireland are dated to around 10,000 BP. By 9,000 BP there were Hunter Gatherer (Mesolithic) settlements throughout Ireland, the new arrivals had adapted to the local ecologies and had learned the local landscapes. It is estimated that the maximum population during this period was about 10,000 people over the whole country. It is also suggested that the first arrivals brought the wild boar with them to supplement their food supply.
A new housing estate was planned at Mount Sandel on the Antrim side of the river Bann in the early 1970s. Over previous years a few stone tools had been discovered in the area due to be developed and a team under Peter Woodman from Queens University were hired to carry out an archaeological dig to test the area in 1973. The dig was exceptionally important and was later carried out over four summers.
Mt Sandal post holes
A number of circular huts 18 feet across were identified through their post holes. Internal fire places in the centre were still filled with the remains of the last fire, including the remains of what they had eaten still preserved.
There was an overwhelming dominance of fish bones (81%) – mainly salmon, with some bass, eel and little flounder. The remains included wild boar, hare, wolf and the bones of 13 different bird species and charred hazelnut shells. Stone tools were found and consisted of microliths along with flake axes, arrows and knives. The site had been chosen carefully beside the River Bann for its food supply – salmon for the spring and summer months, eels from Lough Neagh in the autumn. The bones from young wild boars were mixed with hazel nut shells. The charcoals from the fires in Mount Sandel have been dated to 9,800 BP. Watch this BBC YouTube piece about Mount Sandel
Microlith and stone tools
At the arrival of the first humans to Ireland the sea level is estimated to have been about 20m lower than it is today – ice had yet to melt and flood our seas. It is likely, therefore, that a considerable number of coastal Hunter Gatherer sites have since been flooded by the rising seas.
Map of Mesolithic sites over time
in 1977 an early Mesolithic habitation site was discovered on the shoreline of a post-glacial lake in Co. Offaly. The Lough Boora Mesolithic site was discovered during peat extraction after the lake had been drained. Initial finds of stone tools triggered a full excavation of the site in 1997. The site had been protected by a thick layer of peat that had grown well after the Hunter Gatherers had left. A total area of 2,000 m² was excavated. A large amount of burnt mammal, bird and fish bones were recovered with about 200 microlithic stone tools. No signs of structures survive at Lough Boora, unlike Mount Sandal.
Lough Boora team and site
Radiocarbon dates, particularly from the charcoal found in the hearths provide a date c 9,200 BP for the human presence in the Irish Midlands, slightly later than the dates for Mount Sandel. Botanical analysis suggests that bog started to cover this site about 8,000 BP.
Heavily burnt bones of wild boar, hare, brown bear, wild cat, blackbird, wood pigeon, owl, field mice, grouse and jay were found. The wild boar bones were from a young animal, about 18 months old and killed in summer. There was one bird bone for every three mammal bones, suggesting that bird trapping was carried out locally. Giant deer remains were found below the habitation levels.
Bones from salmon, eel and trout were found. Seasonal fish, such as salmon or eel must have had direct access from Lough Boora to rivers or to the sea. Otherwise, they were caught elsewhere and brought to Lough Boora for consumption.
Almost 200 microliths and polished stone axes, chert, small blade scrapers were also found. These stone tools are clearly associated with ‘Early’ Mesolithic Ireland.
Lough Boora lithics finds
A great part of the interest in the Boora discovery is that its location is in the heart of the Irish Midlands, an area long considered deserted in early prehistoric times. Lough Boora conclusively proves that Mesolithic man colonised the interior of Ireland. It is not possible to accept that the Lough Boora campsite is isolated; other early Hunter Gatherer sites are likely to exist in the Midlands but their discovery is difficult by the massive growth of peat.
Lastly, the most recent find of wild boar remains were found near Lough Boora, at Derrykeel Bog, Longfort in the parish of Clareen, Birr. A tooth from this bear has been dated to 8,800 BP.
These oldest stone tools found in Ireland are remarkably similar to tools found in Scottish Mesolithic sites, whose people lived within 30km from the Irish coast and 65km from Mount Sandel.
What boats were available for the sea journeys to Ireland? The earliest logboats have been found in the North Sea Basin and date about 9,900 BP, all made from pine. Logboats for sea journeys would have to be wider to provide stability than the logboats needed for river or lake travel. The earliest Irish logboats, dated from 6,600 BP were made from oak. This would require mature forests, the use of advanced stone tools, seamanship and navigation skills.
By now traces of the early Hunter Gatherers have been found throughout Ireland. The current known number of Hunter Gatherer sites in Ireland is about 130, although very few have been excavated.
Although the Irish Mesolithic data sources are very scarce, recent aDNA analysis by Lara Cassidy, TCD in 2020 suggests that our first arrivals had dark skin and blue eyes. This changed with the next arrivals who were the first Irish farmers.