Recorded in a wide range of spellings including O'Lenihan, Lenihan, Lenaghan, McLenahan, McClenaghan, McClounan, McClunaghan and no doubt others, this is a Gaelic surname of considerable confusion. What can be said is that all are versions of the ancient names O'Lennachain and Mac Leanachain found in both Ireland and much less so in Scotland. The former name may translate as "the descendant of the long ship", possibly a nickname for a Norse-Viking as the Vikings held much of Ireland in the 9th century, whilst the latter may mean "a possessor of mantles". This is probably a reference to mantles as worn as cloaks, and granted to holders of coats of arms. It may have some indication of nobility, as only those of rank were allowed to wear such clothing. The O'Lenihan clan was originally situated in County Roscommon, whilst two other distinct septs were recorded, the first in County Mayo and County Armagh, the second in Counties Cork and Limerick. In the latter country they were also "erenaghs" or local hereditary lay lords, responsible for the upkeep and preservation of church lands and property in Ardpatrick. The McLenahans' were mostly associated with County Tyrone. It has been suggested that they are of Scottish origin becuse of the 'Mac' prefix, but in fact this can be applied to either Scottish or Irish surnames. The first recorded spelling of the family name is possibly that of Maelciaran O'Lenechan. He was a priest who was mentioned in the "Annals of Loch Ce" in the year 1249. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.