Ireland in the Ice Age

Ireland owes the physcal shape of its landscape almost entirely to the actions of the last Ice Age. The Ice Age left the surface relief much as it now is, except that coastlines have been significantly altered by a subsequent rise of the sea-level caused by the melting of the ice .

For reasons not yet fully understood, our planet goes through cycles of warm and cool periods. The last cold spell began around 30,000 years ago and, in Ireland's neighbourhood, caused the Arctic ice to descend from the North Pole towards Europe. By 20,000 years ago Ireland was almost totally covered by a thick ice sheet stretching south-west from Scotland. Throughout this period the build up of ice on land across the world caused the sea level to drop.  By 20,000 years ago, it had dropped to a level 120 metres (400 feet) below the level it is today.This retreat of the waters meant that Ireland and Britain were once again joined together and joined to continental Europe. On average, 30 to 40km (19 to 25 miles)  of sea bed was exposed around the British Isles.

Thick glaciers and ice sheets would have covered all but the highest peaks and icebergs would have calved into the seas around the island. Little or no vegetation or animal life would have inhabited Ireland.

The Neolithic, or New Stone Age.

The key invention that ushered in the Neolithic Age was farming. This invention fundamentally changed the fabric of Mesolithic society because people no longer had to spend all their time hunting, and they were less likely to go hungry when game was hard to find. Additionally, they could built much larger, more permanent dwellings and, perhaps most importantly, this was the first period that people had enough 'spare time' in which to innovate.

It would be a mistake to think that the Mesolithic people of Ireland suddenly invented farming and became Neolithic. Rather, Ireland's Mesolithic hunters were displaced or assimilated by Neolithic settlers who gradually arrived in Ireland from Britain and brought the technology with them. The practice of farming had spread from the Middle East, through eastern and southern Europe to reach Britain around 4000BC. Again it seems that it arrived in Ireland via the Scotland-Antrim link. Evidence from Cashelkeelty, county Kerry, suggests that this happened between 3900BC and 3000BC.

The Neolithic settlers set about clearing upland forest (which was thinner and easier to clear than lowland forest) with stone axes, or by burning it, in order to build their permanent farms. As Ireland did not have many native cereal crops, and wild pigs were the only farm animals native to Ireland, the settlers brought with them cows, goats and sheep. It is conjectured that these aninals were transported across the Irish Sea on wooden rafts towed by skin-boats or dugout canoes (hollowed tree trunks). They also brought wheat and barley which they planted in their farms. The newly-cleared upland was used for agriculture, but erosion and overgrazing was soon to cause it to stagnate, acidify and eventually evolve into peat bogs. Thus most of Ireland's upland peat bogs (although not the lower ones) are actually artificial features inadvertently created by Neolithic farmers.

Another piece of new technology introduced to Ireland by the Neolithic settlers was the use of porcellanite. This is a rock that is tougher than the flint used by the Mesolithic Irish. It can be used more effectively for making axes, digging tools etc. They found that they could chop down much larger trees than they could with flint tools, and this allowed them to more effectively clear Ireland's upland forests. Porcellanite was mined almost exclusively in county Antrim, in northern Ireland, and two sites have been excavated by archaeologists: Rathlin Island and Cushendall. Axes from these 'factories' have been found mainly in Ulster, but also across Ireland and as far away as southern England. This suggests that, far from being isolated, the Neolithic Irish farmers were trading with Neolithic Britons.

Neolithic farmers may have lived in larger communities than the Mesolithic Irish did, with a number of families living in a cluster of houses with perhaps a larger multi-purpose building in the centre. Evidence from the "Ceide Fields" in county Mayo suggests that these communities may have farmed a considerable amount of land (half a square kilometre in the case of the Ceide Fields). The Ceide Fields are a series of stone field boundaries discovered preserved under peat on the edge of a cliff in county Mayo. At the time they were made, the climate would have allowed them to grow crops there, although today it is a bog. (Note: Ceide is pronounced Kay-je.)

As the Neolithic farmers were not moving around, they were able to build larger and more permanent dwellings. A Neolithic house was rectangular and made either from tree trunks sunk vertically into the ground or from woven branches covered with mud. The gables at each end were supported by a large beam leaning against the ridge of the roof. The roof itself was made from timber beams with reed thatch covering it. A small hole in the roof allowed smoke to escape because, unlike the Mesolithic Irish, the Neolithic farmers lit their fires and cooked indoors. An excellent reconstruction of a Neolithic house can be seen at the Ulster History Park near Omagh, county Tyrone. Note the wattle-and-daub gable wall with the daub (dried mud) removed so that you can see that it is made from finely woven sticks (wattle). Note also the enclosure fence made from a series of vertical logs. We know what these houses looked like because, although most of the wood itself has gone, the post-holes have survived and engineers can thus determine the house's structure.

One final technology that the Neolithic settlers brought to Ireland was pottery. Enough fragments of Neolithic pots have been found in Ireland for it to be reasonably certain how they were made. They were usually made by coiling clay round and round to build up a simple pot shape. These were then smoothed down. Some pots have been decorated by pressing stones, sticks or even fingers into the wet clay. The pot is then hardened by placing it in a hot fire. The pots were used for many things; as well as for storing food, a pot filled with a small amount of fat and set alight was a simple but effective lamp.

Neolithic Megaliths

One of the most important legacies left by the Neolithic farmers was their megaliths, or large earthen constructions, used primarily as burial places. The emphasis placed on these megaliths in literature is mainly due to the fact that they are the only things to have survived largely intact from the Neolithic era. They can thus give us the best clues to Neolithic life, and while they do perhaps over-emphasise the role of burying the dead in Neolithic society, it was also true that burials seemed to have played an important part in Neolithic society. Not only do the megaliths provide many artefacts such as burial objects, but by digging into their constituent material scientists can learn about the climate and vegetation that existed at the time they were built.

Megaliths are not unique to Ireland - they can be found in a broad sweep of western Europe which includes Spain, Portugal, western France, Denmark, Ireland and parts of Wales and Scotland. Nevertheless, with over 1500 recorded megalithic tombs still in existence in Ireland, it is an important aspect of Irish history. The later peoples of Ireland would wonder at these huge enigmatic constructions and frequently attributed them to giants, giving rise to the proliferation of giants in Irish mythology.

The construction of megaliths did not commence with the first Neolithic settlers. Rather, their construction began several centuries after the first arrivals, around 3500BC. They are heavily concentrated in the north of Ireland and can be broken down into three clear types which may be evidence of primitive religious or political groupings (although that term must be used very loosely).

Court tombs

Court tombs are found almost exclusively in the northern half of Ireland: in Ulster and northern Connaught and probably represent the oldest Neolithic constructions. Built mainly in upland areas, a Court tomb basically consisted of a segmented stone chamber covered by an earthen mound, with an entrance courtyard that almost invariably faces east. Today, the earthen mound is usually long eroded away leaving the internal stones of the tomb exposed. While the term 'tomb' is used, it must be said that there is evidence that these structures may possibly have served as temples, rather than simply tombs, and may have been used frequently. Rarely has any intact pottery been found in a court tomb. The best examples of court tombs are Annaghmare, in county Armagh, Magheraghanrush, county Sligo and Tullyskeherny, county Leitrim. There is a large concentration of court tombs in a small area of north county Mayo with other concentrations in counties Sligo, Leitrim, Tyrone and Antrim. The picture is of the court tomb at Deerpark, county Sligo.

Portal tombs

Portal tombs, or dolmens, are found mainly in the northern half of Ireland, but also in the Wicklow - Wexford - Waterford area and around Galway Bay. Probably originating in the east Tyrone area, they may have developed from court tombs. They consist of three or more vertical stones on top of which is perched one or two huge capstones. The capstones always lean down towards one side, leaving a large opening at the high end. Many have collapsed in the intervening millenia, but they remain one of the most striking forms of megalith. Originally, human remains would have been interred inside the tomb and the entrance sealed with smaller stones, most of which have disappeared in the time since.  The best examples are to be found in the Carlingford Lough area of counties Down and Louth. The photograph above shows the portal tomb at Glenroan, county Tyrone.

Passage tombs

Passage Tombs are found in eastern and northern Ireland, although there are a few examples in the south and west. They were built by later Neolithic settlers, probably from western France, and tend to be architecturally more adventurous than court or portal tombs. They consist of a roughly circular earthen mound under which is a central chamber and a passage leading into it. The passage is made from large vertical stones with flat stones laid across them and then covered in soil. In larger examples, the roof of the central chamber tapers in a cone shape and there can be other chambers leading off it. The most celebrated example is Newgrange, county Meath (see below). Perhaps the most interesting feature of passage tombs is their art. Stones both inside and outside them are decorated with swirls, chevrons, eye-motifs etc. These kinds of tomb are shared with Brittany, in western France. Although they originally had vertical sides faced with stones, most have eroded away to become nondescript earthern or rocky mounds.

Newgrange, a passage tomb in county Meath, is arguably the most famous passage tomb in the world, if only because the front half of it has been painstakingly restored to look as it probably did when first built 4,500 years ago. This date makes Newgrange at least as old as the Egyptian Pyramids and older than Stonehenge in England. The beautifully carved stones at the entrance make it a worldwide attraction, as does the fact that the Sun shines directly down the main passage at dawn on the winter solstice around December 21st. At the end of the main passage are three smaller chambers off the main passageway that may have been used for burying theThe entrance to Newgrange [16kB] dead. Newgrange is sited in the Boyne Valley - an area of Ireland that is rich with history. Knowth Passage Tomb lies 1km to the west, while the Battle of the Boyne was to be fought 5km (3 miles) east of Newgrange in 1690. Numerous other megaliths pepper the Boyne Valley.

As will be evident, most megaliths in Ireland are situated in the north part of the island. However, there is a simpler form of Neolithic burial that has been found in the south. Called Linkardstown burials (after a site in county Carlow), they consist of a polygonal stone chamber, paved with stones, and enclosed by large stones that sloped upwards and inwards. A capstone covered the hole at the top. This was then covered in a small mound. Inside has normally been found the remains of just a single human. These 'Linkardstown' burials were on a much smaller scale than the megaliths, and thus not many have survived. Nonetheless, they do seem to be contemporary with their larger contemporaries .