Recorded in many spellings forms including O'Lenihan, Lenihan, Lenaghan, Lenaghen, and McLenahan and McClenaghan, this is a surname of some confusion as to exact origins and meanings. What can be said is that all are versions of the Irish and Scottish Gaelic names O'Lennachain and Mac Leanachain, respectively. The former name may translate as "long ship", a nickname possibly for a Norse-Viking or at least a sailer, as the Viking 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, while 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. This was during the period when Hubert de Burgh, a Norman Irish baron, was Chief Justice of Ireland. Surnames became necessary when governments introduced personal taxation. In England this was known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.