The earliest family of this name hailed from the shores of Loch Lomond, which were granted by the Earls of Lennox to one Absalon around 1225. "Buth chanain"is Gaelic for" house of the canon", and Absalon may have been a clergyman or from one of those families dedicated to the service of the ancient Celtic Church. In 1282 Morris of Buchanan received a charter confirming him in his lands with baronial rights. He also held the small island of Clarench, the name of which was afterwards to become the battle-cry of the clan. The Buchanans supported the cause of Bruce during the War of Independence and the fortunes of the family were thus assured. Sir Alexander Buchanan traveled with other Scottish nobles to fight for the French against Henry V of England, and fought at the Battle of Beauge in Normandy in March 1421. Buchanan's exploits during this battle are given as one explanation for the heraldry of this family: it is said that Sir Alexander killed the Duke of Clarence and bore off his coronet as a trophy, hence the ducal cap held aloft in the crest. The shield, which is virtually the Royal Arms of Scotland, differenced only by changing the lion and the double tressure of fleurs de lis from red to black. This is said to allude to the marriage of Sir Walter Buchanan to the only daughter of Murdoch, Duke of Albany and Regent of Scotland. The regent was ultimately beheaded by his cousin, James I, in 1425, when his vast estates were confiscated. Albany's son had died childless and the Buchanans were the nearest relatives to this disinherited branch of the royal family. The arms are said to mourn the family's loss of status. Also descended from the chiefly family were the Buchanans of Arnprior who held lands in Perthshire around Kippen. The Lairds of Arnprior lived in some style, and were nicknamed the "kings of Kippen". The laird was killed at the battle of Pinkie in 1547.
The ancient lands of Buchanan were to have been passed at the death of the last chief in 1682 to Buchanan of Arnprior, but instead were sold to meet heavy debts. The mansion house of Buchanan is now in the possession of the Graham Dukes of Montrose. Perhaps the most famous Buchanan was the distinguished poet and Protestant reformer George, who was born at Killearn in Stirlingshire in 1506, the third son of Buchanan of Drumkill. He moved to Paris around 1520 to continue his education and traveled extensively on the Continent, embarking upon a literary career. He returned to Scotland around 1560 and in April 1562 he was appointed tutor in classics to the young Mary, Queen of Scots. He received a measure of royal favour but this did not prevent his launching vicious attacks upon the queen in his writings. He was appointed preceptor and tutor to the young James VI after the abdication of his mother, and he is generally credited with laying the foundations for that monarch's considerable academic prowess as well, unfortunately, as poisoning the child's mind against his mother.
James Buchanan was the fifteenth president of the United States of America. There has not been a recognized chief since the late seventeenth century.