Douglas-1, the name of an old Scotch family, believed to be of Celtic origin, and that played a conspicuous part at one time in the internal and external struggles of the country; they figure in Scottish history in two branches, the elder called the Black and the later the Red Douglases or the Angus branch, now represented by the houses of Hamilton and Home. The eldest of the Douglases, William, was a kinsman of the house of Murray, and appears to have lived about the end of the 12th century. One of the most illustrious of the family was the Good Sir James, distinguished specially as the “Black” Douglas, the pink of knighthood and the associate of Bruce, who carried the Bruce's heart in a casket to bury it in Palestine, but died fighting in Spain, 1330.
Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)
Douglas * Douglas, Gawin