From 1821 until 2011, the male and female populations of the 26 counties of the modern-day Republic of Ireland grew at a relatively similar rate, however some fluctuations did occur. During this time, the entire island of Ireland was a part of the United Kingdom of Great Britain and Ireland, after both islands were united by the Acts of Union in 1800. This graph shows the populations of the 26 counties that would later form the Republic of Ireland in 1921, and does not include the six counties that became known as Northern Ireland.

As we can see, both populations follow a relatively similar trend throughout their respective histories. In the first three entries, women outnumber men by 70,000 to 120,000, although these figures do not include military personnel which would narrow this margin. Both populations fall at a similar rate during and after the famine, however the male population does fall slightly faster, possibly due to an increased rate of emigration among males. Another point where both populations differ is in the early twentieth century, where the female population declines in a relatively smooth curve, although the male populations peak in the census data before and after both world wars. From 1956 onwards both populations follow a very similar trend, and grow at the same rate. The difference in population sizes never exceeds 30,000 people, until the final entry in 2011 where the population of men is 2.27 million and the population of women is 2.31 million.

The island of Ireland is split into 32 different counties, and from 1800 until 1921 the whole island was a part of the United Kingdome of Great Britain and Ireland (although Britain had been a controlling presence on the island for considerably longer than this). In 1921 the island was split into two separate states, where the six counties with the highest population of Protestants formed part of the United Kingdom of Great Britain and Northern Ireland, and the other 26 counties became the Independent Republic of Ireland. From 1821 until 1841, the population of these 26 counties was growing steadily, until the Great Famine from 1845 to 1849 swept across the island, particularly devastating the west and south.

The famine was caused by a Europe-wide potato blight that contributed to mass starvation and death throughout the continent, although it's impact on Ireland was much harsher than anywhere else. The potato blight affected Ireland so severely as the majority of potatoes in Ireland were of a single variety which allowed the disease to spread much faster than in other countries. People in the west and south of Ireland were particularly dependent on potatoes, and these areas were affected more heavily than the north and west, where flax and cereals were the staple. As the potato blight spread, the population became increasingly reliant on dairy and grain products, however a lot of these resources were relocated by the British military to combat food shortages in Britain. Due to disproportional dependency on potatoes, and mismanagement by the British government, over one million people died and a further one million emigrated. The Great Famine lasted from just 1845 to 1849, but it's legacy caused almost a century of population decline, and to this day, the population of Ireland has never exceeded it's pre-famine levels.

The population decline continued well into the twentieth century, during which time the Republic of Ireland achieved independence from the British Empire. After centuries of fighting and rebellion against British rule, Irish nationalists finally gained some independence from Britain in 1921, establishing an Irish Republic in the 26 counties. There was a lot of conflict in Ireland in the early 1900s, through the War of Independence and Irish Civil War, however the population of the Republic began growing again from the 1960s onwards as the quality of life improved and the emigration rate declined. The population was at it's lowest from 1926 to 1971, where it remained at just under three million, but in the following fifty years the population has grown by over two million people.

This data collection contains data primarily from both the 1841 and 1851 Census of Ireland used in Fernihough and Ó Gráda (2022). Also contained, where available, are population counts from the 1821 and 1831 censuses. The data collection also includes an amended version of the Civil Parish Shapefile from townlands.ie (OpenStreetMap Ireland, 2020). Both data sources were adjusted to ensure concordance. The towlands.ie data is open data is open data, licensed under the Open Data Commons Open Database License (ODbL). Please contact Alan Fernihough for further details or queries. The “shapefile” files are the GIS files one needs to load the spatial boundaries. The census data is included in the “data.csv” file and one must merge this to the shapefiles to work with these data. However, this is a simple process. The file “load and join.R” is an example of how this could be performed using the R statistical software package.Was early 19th century Ireland overpopulated and fertility at an unsustainable level, or did other factors cause the Great Irish Famine? Did the famine-induced migration to Britain spread infectious diseases and have a substantial impact on British mortality rates? Similarly, what impact did the famine have on the British labour force and economy generally? This research project will answer these questions. The Great Famine was a watershed in global history. It was the last major famine to occur in a Western economy, and had long-run impacts. The enduring legacy of the famine has sparked the interest of numerous novelists and playwrights. Earlier this year, news that media group Channel 4 was considering commissioning a Great Famine-based sitcom stoked an intense public debate. Many felt that this would trivialise the tragedy. The length and breadth of this debate underlined the immense interest that still surrounds the famine. However, the spectrum of opinions as to the causes and consequences of the famine also highlighted the need for further historical research. Let the Data Speak Joel Mokyr's influential 1983 book Why Ireland Starved redefined famine research. Before, famine-related research was largely based on qualitative assessments that left ample room for both conjecture and, rhetoric, and errors. Unlike previous researchers, Mokyr, wanted to let the data decide whether or not it was Ireland's overpopulation that caused the famine. To do this he gathered data on the population density of Irish regions and found that it was Ireland's least densely populated regions that were the ones that suffered worse during the famine. Mokyr's test did not support the overpopulation theory (captured by what is known as the Malthusian model). I hasten to add that the Malthusian model cannot be considered to have been refuted by this finding. For one thing, the possibility that more sophisticated econometric techniques and improved data will reverse the finding cannot be ruled out. (Mokyr, 1983). Whilst striking, Mokyr's analysis was based on variation between relatively few data points (Ireland's 32 counties), as the quote above testifies. This study is motivated by the above quote. Better data (from over 3,000 civil parishes) and more sophisticated econometric techniques exist, and therefore Mokyr's findings can at last be re-evaluated, something this project will do. Mokyr's philosophy of letting the data speak, can also be applied to help uncover some of the Great Famine's consequences. Specifically, this project will quantify the impact that famine-induced migration had on Britain. The famine caused a mass movement of the Irish population to Britain. Before the famine, there were around 430,000 Irish born in Britain. By 1851, the Irish-born population had grown to 730,000. This crisis-driven mass-migration echoes Europe's migration crisis today, as people flea from war-torn and economically desolate nations in Africa and Asia. In this sense, the Great Irish Famine provides a form of historical natural experiment from which we can learn from and gain a greater understanding of the consequences of mass migrations. What effect did the Irish famine have on Britain? This research will use newly available census data (released as part of the ESRC-funded ICeM project) to uncover how the Irish famine influenced the British economy and labour force. For example, did the influx of Irish in certain cities such as Liverpool and Manchester boost demand and help to speed up economic growth, or did this migration depress the wages of locals and therefore stifle economic advancement? In addition, this project will also use newly available records of regional mortality to calculate what impact, if any, the Great Famine had on mortality in England and Wales. If the Irish famine caused elevated levels of mortality, this implies that the ultimate death toll of the Irish famine is underestimated. Parish-level data transcribed from published sources, the official census returns for 1841 and 1851. In addition, to 1821 and 1831 were partially transcribed where they could be satisfactorily matched. Spatial data (shapefiles) were downloaded from townlands.ie. Both the transcribed census returns and the townlands.ie shapefile were amended to ensure concordance between all of the sources. For example, in instances where a civil parish straddled two or more baronies the individual returns for the parish were aggregated to a single data observation, which was then matched to the corresponding townlands.ie spatial polygon. Variables from the 1841 and 1851 censuses are split according to total and rural portions of each parish. The census reports reported the non-rural (towns, villages, etc.) share of each parish separately. In parishes with no non-rural portions (villages, small towns, etc.) the totals for the complete and rural variables will be equal. 58 per cent of parishes fit this criteria.

Abstract copyright UK Data Service and data collection copyright owner.The purpose of the project was to provide machine-readable economic and social history statistics relating to the whole of Ireland for the period 1821-1971. Further information about the project is available on the QUB Centre for Data Digitisation and Analysis website. Main Topics: The dataset contains population census data covering population, housing, religion, birthplaces, language, occupations, age structures, conjugal status and family structure. All the relevant background material is incorporated either in the documentation files or in the scanned images of the tables of contents, prefaces, and notes in the original source. The main population census tables are: Total population grouped by county districts and gender (1881-1971). Total number of buildings, classified as either inhabited buildings, uninhabited buildings, or buildings under construction grouped by county districts. Also includes the area and valuation of each county district (1881-1971). Total number of Roman Catholics, Church of Ireland members, Presbyterians, Methodists and others grouped by county districts and gender (1926-1971). Total number of Roman Catholics, Church of Ireland members and others grouped by counties, gender and age groups (1926-1971). Total numbers born in each county grouped by county of residence and gender (1901-1971) Republic of Ireland only. Total numbers born in each province grouped by county districts of residence and gender (1926-1936) Republic of Ireland only Total numbers born in each county district grouped by county of residence and gender (1926-1971) Northern Ireland only. Irish/English speakers and English only speakers grouped by county districts (1926-1971) Republic of Ireland only. Occupations grouped by counties and gender (1926-1971). Total number of persons in each age group grouped by county districts and gender (1901-1971). Total number of married, single and widowed people grouped by county districts, age groups and gender (1926-1971). Total number of families grouped by duration of marriage, husband's age at marriage, wife's age at marriage and number of children born (1946, 1961 and 1971) Republic of Ireland only. Total number of families grouped by counties, duration of marriage, wife's age at marriage and number of children born (1946, 1961 and 1971) Republic of Ireland only. Total number of families grouped by religious affiliation, duration of marriage, wife's age at marriage and number of children born (1946, 1961 and 1971) Republic of Ireland only. Total number of dependent children grouped by counties, number of children in family and parent's marital status, gender and age (1926 and 1946) Republic of Ireland only. Please note: this study does not include information on named individuals and would therefore not be useful for personal family history research.