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How NI's population has changed in past century

Mark SimpsonCommunity correspondent, BBC News NI
News imageTopical Press Agency/Getty Images/Hulton Archive A black and white archive photo of a group of seven young children, most of them girls, on a cobbled street in Belfast in 1926. Two of the girls are barefoot, one is holding a toddler on her hip. Two others are hiding in an alleyway. The children are mostly smiling. A brick building, possibly a large tenement house, is behind them. Topical Press Agency/Getty Images/Hulton Archive
Census data shows NI's population is older and enjoys more living space and better jobs than it did in 1926 (Photo shows barefoot children in a Belfast slum in 1926)

The counties of Londonderry and Armagh were the fastest growing in Northern Ireland in the past century.

An analysis of census results since 1926 by the Northern Ireland Statistics and Research Agency (Nisra) has tracked the rise of the population from 1.26 million to 1.9 million people.

In terms of counties, Armagh grew by 77% and Derry by 81% while neighbouring Antrim increased by just 32%.

The census in Northern Ireland on 18 April 1926 was the first since the partition of the island of Ireland, but the official records have been lost.

The papers may have been pulped or destroyed during World War Two.

A separate census was held on the same day across the border in the newly-created Irish Free State.

Those records survived, were digitised and at the weekend they were published online for public access.

Although the Northern Ireland paperwork has been lost, the main results were officially recorded and were used by Nisra for their analysis of how Northern Ireland has changed in the past 100 years.

News imagePrint Collector/Getty Images/Hulton Archive A black and white archive print of a large stone gate in Derry city centre which forms part of the city's historic 17th century walls. It has a large, arched entrance and smaller rectangular pedestrian entrances on either side of the arch. Several people are standing at the gates including a young, barefoot boy who is leaning against the stone. Print Collector/Getty Images/Hulton Archive
County Derry's population has risen by 81% since the 1926 Census (Picture shows Bishop's Gate in Derry from "Hutchinson's Britain Beautiful" circa 1924-1926)

Main differences between then and now

Technically, the comparisons are over a 95-year period as the latest census information in Northern Ireland was gathered in 2021.

Among the findings were:

  • Northern Ireland's population has grown by 51% in past century
  • Average household size has almost halved (now 2.4 people)
  • There has been a large increase in people aged 65 or more
  • The percentage of people with no religion has risen from 0.02% to 17%
News imageFox Photos/Getty Images/Hulton Archive A black and white archive photo of a wet and windy day in Castle Place in Belfast city centre, circa 1925. There are tall, ornate buildings lining the cobbled street. Several pedestrians are walking in the rain, some are holding umbrellas. Motor cars and double decker trams are travelling along the street. There is a large union flag flying from one of the buildings.Fox Photos/Getty Images/Hulton Archive
The lost 1926 census was a snapshop of Northern Ireland's population a century ago (picture shows Belfast's Castle Place circa 1925)

Shift in age and religious profile

As previously reported, there has been a significant change in the Protestant-Catholic ratio.

In 1926, about two-thirds of the population (66%) identified as Protestant or other Christian, while 33% were Catholic.

By 2021, much had changed. Catholics were at 42% while 37% were Protestant or other Christian.

One hundred years ago, 189 people stated that they had no religion. In the last census, just over 330,000 ticked that box.

There was also a significant increase in other religions, up from 1,500 people to just over 25,000.

In terms of the changes in the age profile of Northern Ireland over the past century, the Nisra report says there has been a "shift from a young, growing population to one that is older and more evenly spread across age groups".

Society in Northern Ireland has become more diverse.

The percentage of residents born outside the UK and Ireland rose 10-fold, from 0.6% to 6.5%

The timing of the 1926 census was significant, as it showed that life was starting to settle down in Northern Ireland after more than a decade of upheaval.

News imageTopical Press Agency/Getty Images A black and white archive photo of Winston Churchill visiting Queen's' University, Belfast in September 1926. He is seated on a small stage surrounded by a crowd of onlookers. He is wearing a dark overcoat with a large fur collar. Churchill is being presented with a hat and a clay pipe by students during rag week. One of the students is wearing a top hat and a long, fake beard. Topical Press Agency/Getty Images
In 1926 the then Chancellor of the Exchequer Winston Churchill visited Queen's' University, Belfast

'Process of urbanisation'

There was the outbreak of World War One, the 1916 Easter Rising, the Irish War of Independence followed by partition, then the Irish Civil War.

The new border was only confirmed in December 1925, when an Irish Boundary Commission plan to adjust the frontier was ditched.

The historian, Prof Marie Coleman, from Queen's University Belfast, said comparing the 1926 census in Northern Ireland with the one from 2021 shows the pace of change.

"What you see is a process of urbanisation over the course of the 20th century, Derry in particular.

"I suppose Belfast urbanised a lot in the 19th century with the linen industry, but you see a very big growth in the conurbation of Derry-Londonderry. That's one of the big takeaways from it.

"Within those areas, you also see higher levels of educational attainment. That maybe is what is bringing people into the cities.

"But I would say one of the starkest changes over 95 or 100 years is the number of people staying on in education."

The full report from Nisra can be found on its website.

The next census in Northern Ireland is due to take place in 2031.