The name Allanach conclusively comes from Scotland and is Scottish Gaelic in origin. This comes from research at the University of the Highlands. Link here.
There are many variants – Alanach, Allanoch, Alanack, Allenach, Alnach, but the most common spelling is Allanach. The History of The Clan Macfarlane refers to the Allanachs as ‘Na Allanich’ which would perhaps be ‘Na h-Allanaich’ in modern Scots Gaelic.
The Allanachs all originate from extended families living around the Parish of Strathdon. I showed this by mapping all Allanachs in 1695 here. The first recorded Allanach – Finlay Allenoch in 1588 who resided at Innernete (Towie, 7 miles from Strathdon).
There are perhaps three theories as to the origin of the Allanach name.
1) ‘The Son of Allan’
The majority view is that the name means son of follower of Allan, specifically Allan MacFarlane. The History of The Clan Macfarlane states, “the family of Allan or McAllan is one of considerable importance. Their progenitor, Allan MacFarlane, a younger son of one of the Chiefs of Arrochar, settled in the north of Scotland, and his sons, instead of taking the family patronymic, called themselves sons of Allan, just as, in another case, the sons of Thomas, younger son of Duncan, the 6th Chief, called themselves Thomas’s sons instead of MacFarlane.
Allanson and Allanach are variants of MacAllan, adapted from the Gaelic, Aluinn, signifying illustrious. The principal locations of the family are Mar, Strathdon, Glenbuchat and Glenmuick.”
2) ‘Scotsman’
‘Albannach’ in modern Scots Gaelic means ‘Scotsman’. I heard a theory that our name is derived from the word but have only seen one variant in the records spelt ‘Albanach’ so would think unlikely.
3) ‘Water of Ailnack’
Another theory is that the name descends from the Water of Ailnack based on the original Gaelic spelling of Uisge Ailneag (close to ‘Allanach’ is pronunication). The theory is that the Ailnack would have either taken the name from the original family living there, or the families living there would have taken their name from it.
At 600 ft wide, 300 ft deep and 6 miles long, the Ailnack Gorge is Scotland’s largest glacial melt water channel. A short distance from Tomintoul, it also is certainly within the area in which the original Allanachs resided.
The theory is strengthened by a book from the 1600s which calls the Ailnack the Waters of Allanach. I am positive I have seen this online in my earlier days of research but unfortunately cannot re-find it. Until I can, this theory perhaps also remains an outside possibility
