Despite their name the Bain family were not part of the Scottish Clan MacBean. They were in fact a branch or sept of the Clan Mackay, another Highland Scottish clan. The progenitor of this family was John Bain Mackay, otherwise known as John Bàn (Bàn is gaelic for 'fair' as in fair-haired)'. John was the son of Neil Neilson Mackay who was in turn a grandson of Donald Mackay (died 1370), chief of Clan Mackay. John Bain Mackay dropped his surname and used his middle name of Bain as a surname instead. This may have been due to a feud within the Clan Mackay involving his father Neil Neilson Mackay that had resulted in the Battle of Drumnacoub in 1427 or 1433. Due to this conflict John Bain not only dropped the surname of Mackay but moved from the his homeland in the west of the county of Sutherland to the neighboring county of Caithness.
John Bain married in 1436 and died in 1452, leaving four sons:
- John Bain, born 1437, progenitor of the Bain families of Caithness and Haddingstonshire (East Lothian).
- William Bain, born 1438, progenitor of the Bain families of Clyth.
- Alexander Bain, born 1440, progenitor of the Baynes of Tulloch and Dingwall. This family were seated at Tulloch Castle and fought at the Battle of Logiebride in 1597 as allies of the Clan Munro.
- Donald Bain, born 1443, settled in Galloway.
- Mackay, Angus. (1906). The Book of Mackay. (St Andrews University). Printed by William Rae, Wick. pp. 50.
- History of the House and Clan of Mackay (page 73). Author: Robert Mackay, Writer, Thurso. Published Edinburgh 1829.
- Bains of Dingwall - a history
- a history of the Bains of Tulloch - The Clan Mackay Association of Canada
- Clan Mackay of Canada. "Bain, Bayne". clanmackay.ca. Retrieved 11 August 2012.
- Foulis Press. (1764). The History of the Feuds and Conflicts Among the Clans in the Northern Parts of Scotland and in the Western Isles: from the year M.XX1 unto M.B.C.XIX. (First published from a manuscript written by Sir Robert Gordon in about 1625).