Morton / Mortoun was accepted as a sept of Douglas by CDSNA at its organization in 1975 based on the original list from the book Scots Kith and Kin.
The following notes pertaining to The Douglases of Morton can be found in George Harvey Johnston’s 1907 edition of The Heraldry of the Douglases: With Notes on All the Males of the Family, Descriptions of the Arms, Plates and Pedigrees, pages 63-65. These notes detail how the Douglases received the lands of Morton. Sir James Douglas (No.257 in Johnston’s pedigree) would be the first Douglas to be styled “of Morton” and his grandson James, Third Lord Dalkeith, would be created the first Earl of Morton in 1458 after his marriage to Joan, “the dumb lady” daughter of King James I.
It should be noted here that Archibald Douglas, father of Andrew Douglas (No. 251) and Sir William “Long Legs” de Douglas, father of Sir William “le Hardi” Douglas, are believed to be brothers making Andrew Douglas and William “le Hardi” first cousins.
The Douglases of Morton.
The account of this family is based on Douglas’ Peerage, Complete Peerage, Maxwell’s History, and brought up to date by Burke’s Peerage. Official Records and other authorities mentioned in the text.
(251) ANDREW DOUGLAS OF DOUGLAS is generally believed to be the younger
son of Sir Archibald de Douglas (No, 2), as he succeeded to the estates of Herdmanston and Livingston, which had been acquired by his supposed father between 1214 and 1226. He had a son: -
(a) William (No. 252).
and Douglas in his Peerage gives a second: --
(b) Frisken, ancestor of the Douglases of Pumperston. (No. 406).
(252) WILLIAM DOUGLAS OF HERDMANSTON living 1277. He married Elizabeth daughter of Alexander, High Stewart, and is said to have been father of: --
(a) Sir James (No. 253).
(b) Sir Andrew Douglas, living 1351.
(253) SIR JAMES DOUGLAS OF LOTHIAN had charters of Kincavill and Caldercleir in 1307. He left: --
(a) Sir William (No. 254).
(b) Sir John (No. 255)
(c) Sir James Douglas, killed 1335.
He also left a natural son: --
(d) William Douglas.
(254) SIR WILLIAM DOUGLAS, known as the Knight of Liddesdale, was born about 1300. In August 1353 he was killed by his cousin, William Douglas (No. 8), leaving only a daughter, Mary.
Arms on Seal, 1345. – On a chief two stars. CREST: A boar in front of a tree.
SUPPORTERS: Two savages (MacDonald). [Plate VI., fig. I.]
His brother: --
(255) SIR JOHN DOUGLAS, and also the following sons, by his wife Agnes Monfode, are mentioned in the Will of the Knight of Liddesdale: --
(a) James (No. 256).
(b) Thomas Douglas.
(c) William Douglas.
(d) John Douglas.
(e) Henry (No. 318).
Douglas’ Peerage also gives: –
(f) Nicolas(?) ancestor of Douglas of Mains (No. 392).
(256) SIR JAMES DOUGLAS OF DALKEITH, married in 1372 Agnes, daughter of Sir Patrick Dunbar, and sister of George, tenth Earl of March, who brought her husband the lands of Morton, etc., and died before 1384. He married secondly Giles, daughter of Walter, sixth High Stewart. He died in 1420. By only his wife he had issue:--
(a) Sir James (No. 257).
(b) Sir William Douglas.
He had also two illegitimate sons: –
(c) John Douglas of Aberdour.
(d) Sir James Douglas of Aberdour, Robertson, etc.
Arms on Seal, 1371. – On a chief two stars. CREST: A boar passant between two trees. SUPPORTERS: Two demi savages (Laing). [Plate VI., fig. I.]
Johnston, G H. The Heraldry of the Douglases: With Notes on All the Males of the Family, Descriptions of the Arms, Plates and Pedigrees. Edinburgh: W. & A.K. Johnston, limited, 1907. Print.