Although there has been a national census taken every decade in Ireland since 1821, the majority of 19th- century returns have been destroyed, with only fragments surviving between 1821 and 1851. Fragments from Antrim, Derry, Fermanagh and Cavan have been published online by the National Archives of Ireland ( census.nationalarchives.ie), along with the complete 1901 and 1911 censuses.
Candidates for the pension who could not provide a birth certificate used the 1841 and 1851 census to prove their age. They applied to have the census searched for their family return and these Census Search Forms contain family details, such as mother’s maiden name and townland address. The forms for Ulster are available on microfilm in the Public Records Office of Northern Ireland ( PRONI).