Irish research has a (somewhat justified) reputation for being difficult. But even though many records have been destroyed over the years, you can still find your ancestors’ records by knowing where and when they lived.
Poor law unions (PLUs), designed by the British government to administer services for the poor, are central to this research. Although no longer in use, PLUs did serve as the basis for superintendent registrar’s districts, the units created when Ireland began its genealogically crucial civil registration system in 1864. The two kinds of districts shared boundaries and are identical, from a family historian’s perspective. By knowing the PLU your ancestor lived in, you’ll know where to find him in Ireland’s civil birth, marriage and death records.
The map above—which you can download in letter-size, printable form—displays PLU boundaries (and thus, the superintendent registrar’s district boundaries) that were used in the civil registration system. PLUs varied in size, from larger in the western part of the island (where population was more sparse) to the smaller in the east (where the population was more dense).
For more information on PLUs, civil registration records and other crucial aspects of researching your Irish ancestors, consult The Family Tree Irish Genealogy Guide by Claire Santry, a comprehensive guide to identifying immigrant ancestors and tracing them back to Ireland.