Census' where held every ten years in Ireland, starting in 1821. Unfortunately the census' for 1861, 1871, 1881, and 1891 where turned into pulp by government order during World War One. The reasons for this is unknown and at best speculation. One theory is that it was to hide the impact of the Great Famine in Ireland between 1845-52, yet population statistics remain collated from those census'.
A further disaster for family tree enthusiasts struck during the Irish Civil War in 1922-23 when the IRA purposely set about soaking records in petrol and setting them on fire in the Public Records Office in Dublin. The result was the mass destruction of historical documents going back to the 12th century. As a result many important documents where forever lost including a lot of church records and the census' for 1821, 1831, 1841, and 1851. The 1901 and 1911 census' survived intact.
Whilst these early census' where not very in-depth, the information to be found can be useful in tracing certain people to specific areas. The information recorded in each census varied.
A minor consolation is that small fragments of these burnt census' do survive for parts of Ireland such as a specific parish or in the case for 1831, the entire county of Londonderry. The following Excel file lists the forty-one Richardsons to be found in Ulster in these surviving fragments:
