Vikings arrived in Ireland when the population was in serious decline

Vikings arrived in Ireland when the population was in serious decline
Credit: Queen’s University Belfast

New research has found that the population of Ireland was in decline for almost 200 years before the Vikings settled.

The research from Queen's University Belfast's School of Natural and Built Environment is the first of its kind and has been published in the Journal of Archaeological Science.

Previously it was thought that the population of Ireland gradually increased over the years. However, the researchers have found that the population was in serious decline for almost two centuries before the Vikings migrated.

Using rigorous archaeological data science algorithms, the experts have released an estimate of past population numbers. The data shows the importance of migration as without the Vikings, the population decline could have been much worse.

Dr. Rowan McLaughlin, Research Fellow from the School of Natural and Built Environment, explains: "Millions of people lived in Ireland during prehistory and the earliest Christian times.

"Around the year 700, this population in Ireland mysteriously entered a decline, perhaps because of war, famine, plague or political unrest. However, there was no single cause or one-off event, as the decline was a gradual process."

He adds: "The Vikings settled in Ireland in the tenth century, during the phase of decline and despite being few in number, they were more successful than the 'natives' in expanding their . Today, suggests many Irish people have some Viking blood."

For the study, the researchers used a database of archaeological sites discovered during the "Celtic Tiger' years, when there was a boom in motorway building and other development in Ireland.

Developers are required by law to employ archaeologists to record sites before they are destroyed. This allowed the researchers to access information that was not previously available.

Dr. McLaughlin commented: "This has opened up a completely new perspective on the past that we simply could not obtain any other way."

Emma Hannah is the lead author of the paper and is taking the work further with her Ph.D. research. She explains: "Often in archaeology we are focused on interpreting the evidence from a single site, but analyzing quantities of data in this way allows us to think about the long term. Now we know these broad trends, we can better understand the details of everyday life."

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Viking migration left a lasting legacy on Ireland's population

More information: Emma Hannah et al. Long-term archaeological perspectives on new genomic and environmental evidence from early medieval Ireland, Journal of Archaeological Science (2019). DOI: 10.1016/j.jas.2019.04.001
Citation: Vikings arrived in Ireland when the population was in serious decline (2019, August 22) retrieved 19 September 2019 from
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Aug 22, 2019
Unfortunately the full paper is pay-walled, so there's no easy way to check the the data or even the methodology. But I am not changing my view of the Viking invasions of Ireland until I see something more convincing.
The first Viking raids in Ireland began in the 790s and the conventional history would expect that the Irish population declined from AD 800 to 1000 because of depredation and social turmoil. The authors assert that the population decline actually began about 700 for 'mysterious' reasons and continued at least 200 years. (Their population estimates are paywalled so I am using their text.)
So their main challenge to conventional history is to claim that a longterm downtrend in the Celtic Irish population had begun about 700, and that Viking "migration" kept the population from declining even more. These are big claims, and I am not nearly convinced.

Aug 22, 2019 hops many paywalls.


Aug 22, 2019
Those Vikings were a randy bunch...

Aug 22, 2019
my opinion includes both shake's & the research in this article

there is a lot of different reasons for population declines in late roman to medieval periods

to avoid usurious taxes & conscription for life in the army, young men fled into the monasteries
too many mouths to feed at home?
young women were sold to the nunneries or sold for export

the "vikings in the early viking period, were a mishmash of sell-swords from all over the islands & mainland europe
with their diseases, better weapons & nasty attitudes

they were recruited by irish kings who didn't trust their vassals & losers at blood-feuds

both importing foreigners to retake whatever the loser thought he was due

another consideration was the lack of genetic diversity among the original "irish" peoples combined with limited nutritional choices & a terrain mostly only useful for grazing animals

all too many people do not realize or appreciate the centuries of effort it takes to "manufacture" decent farmlands

Aug 22, 2019
Thank you, Doug Nightmare. The full article provides a lot more information, including graphs. But the authors are still keeping their basic data, algorithms, and error estimates close to their vests. This is a shame, because these are possibly the best estimates of the population of Ireland prior to 1200 AD. I wish the article were about developing and improving this still-fuzzy data, instead of using it to advance a questionable theory about "Viking migration". But articles about Vikings get a lot more press than population estimation analyses.

Aug 23, 2019
@rrwillis, You've suggested a lot of possibilities, and I'm of the opinion that diseases are probably the most important factor.
The full article contains a graph of population estimates for Ireland from 400 BCE to 2000 CE, and it is interesting but it needs to be analytically probed. Their medieval population estimates are very dramatic -- The population of Ireland was estimated at less than one million in 350 CE, but by 700 CE it was over 3.5 million. From 700 CE to 1500 CE, the population estimates decline from 3.5 million to about 1 million.
The numbers don't provide much support for the benefits of Viking 'migration': Even if population decline started in 700, the declines were very great during the Viking era (800 to 1050 AD) and the Norman era (1168 to 1485).

Aug 23, 2019
OOPS! My comment above has a typo -- the full article's population estimates extend from 4,000 BCE, not just from 400 BCE. It's a very impressive undertaking.

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