Thomas Buchanan, the first of Drummakill, was the third son of Sir Walter Buchanan of that Ilk.
A charter in his favour, granted by Patrick Buchanan of that Ilk, his brother, of the lands of Gartincaber, to be held blench of the said Patrick, is dated at Buchanan 1461.
He also held a charter dated at “Trefichin”, 3rd. February 1461-2 of the Temple lands of Letter. Thomas acquired other lands over several years and appears to have been in possession of Drummakill by 1495.
His wife, of whom little is known, seems to have been called Donota, and bore him three sons.
1. Robert Buchanan second of Drummakill
2. Thomas of Carbeth
3. Walter of Balwill.
Robert Buchanan second of Drummakill married about 1472 Margaret Hay of Dullievairdis. Robert and Margaret had two sons
1. Thomas who died young and long before his father
2. John who is the ancestor of the Buchanan’s of Wester Cameron.
Thomas Buchanan married Agnes Heriot and by her had five sons and three daughters.
1. Robert who succeeded his grandfather
2. Thomas afterwards of Drummakill
3. Alexander of Ibert – ancestor of the Buchanan’s of Ballochruin
4. Patrick
5. George who became internationally famous – poet, statesman, and tutor to James VI/I.