The general pattern of geographic distribution of the major religious denominations in modern Ireland was established by events of the sixteenth to eighteenth centuries. Native Irish "occupiers" of the land generally were Roman Catholic, but many of them were displaced from certain areas by Protestant settlers from England and Scotland. Meanwhile, the "ownership" of the land in most areas was transferred from Gaelic and Old English elites, who were still largely Catholic in the seventeenth century, to a New English elite composed of members of the Protestant Established Church. These transfers—together with some conversions of Catholic landlords in the eighteenth century—ensured that there was at least a small Protestant minority composed of landlord families and their retainers in nearly every part of Ireland in the nineteenth century.
The earliest census that provides reliable and consistent parish-level data on adherence to each of the major religious denominations throughout Ireland was conducted in 1834. The first map here is based on these data and offers a snapshot of Irish religious geography about halfway through the period since the general pattern was established. The proportion of Protestants in the population, which may have been higher in the eighteenth century, was declining in many areas by the mid-nineteenth century, and that decline was accelerated in southern Ireland after independence in 1922. At present Protestants constitute less than 5 percent of the population of the Irish Republic.
The religious geography of Ulster reflects not only the displacement of Catholics by Protestant settlers but also the division among those Protestants between immigrants from England, who generally adhered to the Church of Ireland, and those from Scotland, who mostly retained the Presbyterianism of their mother country. At least as late as the 1790s that division within Protestantism was very important politically. Anglicanism dominated a zone based in the Erne valley in the southwest of the province and another zone in the lowlands around the southern shore of Lough Neagh. Usually, lowland territory is agriculturally more desirable; significantly, Catholics and Presbyterians had to settle for the less desirable uplands adjacent to these zones. Presbyterians did, however, dominate the mouth of the River Lagan as well as the Lower Bann valley (known locally as "the Route") and the Foyle valley (known, confusingly, as "the Laggan"). As a result, the two leading towns that developed in post-plantation Ulster, Belfast and Derry, were Presbyterian strongholds in the eighteenth century.
The industrialization of Belfast in the nineteenth century led to heavy migration from the countryside, including both Anglican and Catholic workers. As Presbyterians lost their majority position in the city, and as the political tensions between Anglicans and Presbyterians lost their salience, Belfast developed more or less clearly demarcated Protestant and Catholic working-class neighborhoods. A similar process happened in Derry, which is now a predominantly Catholic city. Such segregation became even more thorough during the "Troubles" that began in the late 1960s. Although the refusal of many persons to state their religion in recent censuses makes precision impossible, it appears that the present population of Northern Ireland is about 42 percent Catholic (compared with about 35 percent in the 1960s).
SEE ALSO Landscape and Settlement
Compton, Paul A. Northern Ireland: A Census Atlas. 1978.
Vaughan, W. E., and A. J. Fitzpatrick, eds. Irish Historical Statistics: Population, 1821–1971. 1978.
David W. Miller
"Religious Geography." Encyclopedia of Irish History and Culture. . Encyclopedia.com. (January 20, 2019). https://www.encyclopedia.com/international/encyclopedias-almanacs-transcripts-and-maps/religious-geography
"Religious Geography." Encyclopedia of Irish History and Culture. . Retrieved January 20, 2019 from Encyclopedia.com: https://www.encyclopedia.com/international/encyclopedias-almanacs-transcripts-and-maps/religious-geography