The family of Buchanan of Ballat is descended through Thomas Buchanan of Carbeth, who was a younger son of Thomas Buchanan of Gartincaber and Drummakill. Thomas, first of Carbeth, had two sons, (1) Thomas who succeeded to Carbeth, (2) John in Easter Ballat.
Arising out of this family we have the cadet line of Blairlusk, and in the second generation Margaret Buchanan daughter of George Buchanan of Blairlusk, married George Buchanan of Blairennich and Finnick Drummond and became the grandparents ( 5 times removed ) of C.A.B.
With regard to Alexander the bearer of these arms, he is described in Lyon Register as ”late of the 95th now Captain in the ninth Regiment of Foot, son and heir of John Buchanan of Ballat, who was son and heir of Andrew Buchanan of Ballat, the eighth generation in the paternal line from Thomas Buchanan of Carbeth, who was third son of Sir Walter Buchanan of Buchanan by Lady Isobelle, second daughter of Murdoch Duke of Albany and Governor of Scotland, son and heir of Robert Duke of Albany also governor of Scotland, and third son of King Robert II•.

I suggest that there may be a slight error in the recording of the information regarding the family, as I believe that Thomas Buchanan, first of Carbeth was a younger son of Thomas Buchanan of Gartincaber and Drummakill, and had a conveyancing from his father of the lands of Carbeth 31 May 1482 and died before 1493. He would therefore have been a grandson to Sir Walter and not a son. The error of one generation makes little difference in this case as the family are quite clearly descended through Sir Walter.

The arms are recorded in Lyon Register Volume 1, Page 264-5, 7 August 1784.

THE ARMS: Or, a lion rampant Sable, armed and langued Gules, within a double tressure flory counterflory of the second, all within a bordure engrailed of the third.

THE CREST: A dexter hand holding a dagger in pale both Proper.

THE MOTTO: 'Sanguine Inscribam' ( I wrote in blood )