Around 1000bce Ireland was coming to the end of the Bronze Age and on a largely parallel path to England. The population was growing, people were moving to fortified hills, militarism was on the rise observable in both burials and new polities and their power-bases. However within a few centuries Ireland was to take a mysterious divergent course, a course that makes the Iron Age the most obscure period of Irish archaeology and lead to Barry Raftery dubbing the Iron Age Irish the ‘invisible people’.
The iron age began in Ireland about 700 BCE and sort of ended 600 BCE as it failed to take hold. For the next five centuries Bronze (despite abundant supplies of bog ore) continued to be the preferred metal for the next 5 centuries across the country apart from a few sites across the north. With the Iron age in full swing across Europe, populations booming, the population of Ireland suddenly started to diminish. Archaeologist Barry Cunliffe studying this anomaly noticed that tree rings showed large scale forest regeneration in the period suggesting a substantial decline agriculture. Rich burials also disappeared at this time. While the gold hoards are being buried with kings in Britain and across Europe, Irish burials become increasingly impoverished.
Reasons for the ‘unique’ decline of Ireland in this period remains a mystery. It has been suggested the appearance of hill forts and Raths in the period shows that widespread warfare could be the cause, but as exactly the same was occurring in Britain, that was prospering, so this is unlikely. Iron Age Ireland remains one of archaeology’s mysteries.
This graph from “Iron Age Ireland, Finding the Invisible People” by Katrina Becker, John O’Neal and Laura Flynn. In a recent survey of all all Iron Age sites illustrates the drop in population.
One solution may be that between 700bce and 500bce temperatures dropped a full two degrees, this was known as the Sub-Atlantic-Period.
Nigel Wright (“Separating Romans and Barbarians” MA thesis) says in Upper Teesdale circa 600 BC;
“large scale clearances increased erosion, leading to the spread of moorland across a wide area along with increasingly waterlogged and acidic soils. These depleted soils were incapable of sustaining forest regeneration.”
As the agricultural land dropped to a minimum, Raftery suggest the remaining Irish returned to a more nomadic lifestyle, but this weather change wouldn’t have effected Ireland in isolation but Britain as well. So why wasn’t Britain devastated?
What seems to have happened is as the climate changed it became wetter and farming more difficult the English moved their farms onto higher lands. This corresponds with the boom in Hill-forts surrounded by farms on the slopes. The British were driven to the hills but still flourished.
Thinking for a moment this contradicts everything I learnt in archaeology class, that the British moved to the hills because of overpopulation causing widespread warfare and the need for defence. As for the Irish, why didn’t they do the same. Simply, Ireland unlike Britain is a relatively flat country, there wasn’t the highlands to move too.