Northern Ireland now has more Catholics than Protestants for the first time, new census results have revealed.
It represents a historic shift that could help to drive support for a united Ireland.
Northern Ireland was established in 1921 with the aim of maintaining a pro-British, Protestant "unionist" majority against the newly independent, mostly Catholic, Irish state.
The 2021 census shows 45.7% of respondents identified as Catholic or were brought up as Catholic, compared to 43.5% as Protestant.
In 2011, the previous census revealed Protestants outnumbered Catholics 48% to 45%.
Sinn Fein leader in the North Michelle O'Neill said "Today's results are another clear indication that historic change is happening across this island."
Sinn Fein said the shift was a further reason why planning should begin for a referendum on a united Ireland.
The party has increased calls for a unity poll since Britain's decision to leave the EU in 2016, which 56% of Northern Irish voters opposed.
Demographers have long predicted that Catholics, who tend to be younger and have higher birth rates, could become a majority of voters within a generation.
The census results also show the proportion of people with no religion jumped to 17% from 10%.
Another census question found that 32% of respondents identified solely as British, down from 40% in 2011, with 29% seeing themselves as Irish, up from 25%.
A further 20% said they were Northern Irish.
The #NICensus2021 asked everyone in #NorthernIreland the same questions.@NISRA have released results for Newry, Mourne and Down
Visit https://t.co/olEJo7rX5l to find out more about your council area with the @NISRA #AreaExplorer
https://t.co/0ARV5aULjH@nmdcouncil pic.twitter.com/xfhUv8l9bZ— Census 2021 - Northern Ireland (@NICensus2021) September 22, 2022
