The first reference to this townland, according to the Ordnance Survey Name Books, was during the reign of James I (1603-1625), and again during the reign of William III (1689-1702). The standard name was given as Rathmoreahanduff and again as Rathmore Ahanduff. The Irish form was Rath Mór, meaning great fort. Its official Irish version today is Ráth Mór An Átháin Dhuibh. Both George D.H. Kirkaldy and Rev. Francis Coghlan wrote the name of this townland as Rathmore Ahanduff.
Rathmoreahanduff lies adjacent to Derrysiskal, Corry, Ahanduffmore and Rathmore Demesne. In the 1830s it contained two houses and one ruin, was intersected with ditches and drains, and had about six acres of bog. The remainder of the land was described as arable and pasture.
Census 1841, 1851
Census statistics recorded eight people in one house in 1841 and surprisingly, after the famine, nine people in the one house in 1851.
Griffith’s Valuation 1855
Griffith’s Valuation gave the total acreage as eighty eight acres, two roods and nineteen perches, at a total annual valuation of £36.8s.0d. James McDermott owned all of the land and retained eighty two acres and twelve perches for himself. He leased out the remainder of the land to two tenants. James Kane held a house on five acres and thirty six perches of land at a total annual valuation of £2.0s.0d. Anne Larkin held one acre, one rood and eleven perches, but did not have a house on the land.
Census 1861, 1871, 1881, 1891
Census statistics for 1861 showed four people living in two houses in this townland. Statistics for 1871, 1881 and 1891 denoted the absence of population and houses.
The 1901 census shows that there were no houses or population for the townland of Rathmoreahanduff.
The same applied in the 1911 census for Rathmoreahanduff.