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The Imprint of Finality? Partition and Census Enumeration

18 April 2024

Paul Nolan

This article is part of a special section of ISIA, edited by Brice Dicksen. See the other papers in the section


The partition of Ireland in 1921 drew heavily on the census data of 1911 to determine how the boundary between North and South was to be demarcated. The intention was to ensure a numerical advantage for the Protestant population in the new Northern Ireland, sufficient to ensure a permanent unionist majority. The publication of the data from the 2021 census in Northern Ireland and the 2022 census in Ireland allows for an assessment of how the demography has changed over the past 100 years, and the extent to which the changed ratio of Catholics and Protestants calls into question the longer-term viability of Northern Ireland as a polity. The article goes beyond the Catholic–Protestant binary to look at the growth in numbers of those with other faiths and those with no religion, and the impact of secularisation on the island of Ireland.


In 1936 Nicholas Mansergh, father of Fianna Fáil politician Martin Mansergh, published The Government of Northern Ireland: A Study in Devolution.1 Written fifteen years after partition, it was the first assessment of the UK's novel constitutional experiment. Mansergh wrote that while the new settlement had shown itself 'more durable than was expected in some quarters', it still did 'not bear the imprint of finality'. In recent years that imprint has become even more elusive. Newspapers regularly carry opinion polls on reunification, and a slew of new books consider the prospects of epochal constitutional change on the island.2 The coincidence of a census taking place in Northern Ireland on the centenary of partition prompts a questioning of the durability that Mansergh observed. This article looks at the Census 21 results, and suggests that while the new Catholic plurality is an inflection point in the evolving relationship between the two main communities, the traditional unionist–nationalist binary has been superseded by a more complex dynamic in which a diverse set of identifications has emerged. While proponents of a border poll lean heavily on a form of demographic determinism, the article suggests that the census figures do not provide evidence of the 'inevitability' that is frequently invoked.3

Instead, it is suggested that demographic changes over the 100-year period are best viewed as a series of ironies. The first irony is that the Northern Ireland political unit, set up to ensure a permanent Protestant majority, now contains more Catholics than Protestants. The second irony is that while the prospect of a border poll has had a polarising effect, with heightened emotions on both sides, the numerical equilibrium between northern Catholics and Protestants means that the deciding votes in any future poll would be cast by those with least interest in the debate, newcomer communities and those with no religion. The third irony is contextual: in 1921 a heavily industrialised and prosperous community in the north-east did not want to be ruled by the government of a country that was largely agrarian and appeared likely to pursue protectionist tariffs that would cut the North off from the vital trade links afforded by being part of the UK. Home rule seemed to unionists to threaten 'home ruin'.4 One hundred years on, the Northern Irish economy is dependent on subsidy to survive while the Irish economy is generating budget surpluses that leave the government with more money than it can easily spend, and is consequently offering some financial support to its more impoverished northern neighbour.

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1. Nicholas Mansergh, The government of Northern Ireland: a study in devolution (London,1936).

2. See, for example, Brendan O'Leary, Making sense of a united Ireland: should it happen? How might it happen? (Dublin, 2022); Padraig O'Malley, Perils and prospects of a United Ireland (Dublin, 2023); Malachi O'Doherty, Can Ireland be one? (Dublin, 2022), Ben Collins, Irish unity: time to prepare (Edinburgh, 2022).

3. There have always been claims that a united Ireland is inevitable, but a sample of headlines in September 2023 will serve to illustrate the increased volume of these claims. On 7 September 2023 the BBC NI website led with this headline: 'Leo Varadkar says Ireland on a path to reunification'. Varadkar's comments were supported by SDLP leader Colum Eastwood, who suggested that given current trends the year 2030 should be set for a border poll on the issue (Irish News, 8 September 2023). On 15 September former President Mary McAleese said 'It's undeniable that demographics are shifting towards a united Ireland' (Irish News, 16 September 2023). Bono said he 'could see a united Ireland in his lifetime' (Irish Mirror, 29 September 2023). Predictions of a united Ireland were not limited to nationalist commentators. In a surprise development the veteran DUP politician Wallace Thompson gave an interview to the Belfast Telegraph in which he conceded the inevitability of a united Ireland: 'Unionism was probably always doomed: A "new Ireland" is now inevitable says DUP founder member' (Belfast Telegraph, 4 September 2023).

4. See Alan de Bromhead, Robin Adams and Ciaran Casey, 'Ireland's economy since independence: what lessons from the last 100 years?', Economics Observatory, 30 April 2021, available at: (2 November 2023). The period just before 1921 marked the zenith of the northern industrial economy. The Belfast News Letter described 1919 as the annus mirabilis of the linen industry, and it also marked the peak for Harland and Wolff, with a workforce that had grown to 30,000. See Charles Townsend, The partition: Ireland divided 1885–1925 (London, 1921), 161. These successes were seen as due to the integration of the North's industries with British markets.


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