William Douglas - Possible Duplicate Persons?

The Scots Peerage 1904-1914, nine volumes , Paul, Sir James Balfour. 6:350-1

https://archive.org/details/scotspeeragefoun06pauluoft/page/350/mod...

Sir James Douglas, 1st Lord of Dalkeith married twice, a son William by each marriage.

By 1st wife Elizabeth Stewart, Princess of Scotland son William Douglas who married Margaret Borthwick

http://fmg.ac/Projects/MedLands/SCOTTISH%20NOBILITY%20LATER.htm#Jam... Is a bad link now, the page must have moved.

WILLIAM Douglas of Whittinghame in East Lothian (before 30 Sep 1390-[1425]).

That title was assumed by his younger 1/2 brother after his death.

TSP has:

William, born, as indicated, before September 1390, when he is named in his grandfather's will. He was in 1405 one of the hostages who went to England for Archibald, fourth Earl of Douglas, and he seems to have remained a prisoner in England until May 1413, when his grandfather paid 700 merks for his libera- tion. He appears also to have been one of the hostages for King James I., and was still in England in 1425,3 when he probably died, as he then disappears from record, and his next brother succeeded to their father. On 9 December 1420 a dispensation was issued for his marriage with Margaret Borthwick, widow, not of Sir William Abernethy, as stated by some, but of his son William, who had been slain at Harlaw in 141 1.4 By her he had no issue.

Sir James married 2nd to Janet Borthwick with son Sir William Douglas, 1st of Whittinghame who married 2nd to Margaret Dunbar (according to the profile manager).

TSP has (page 352)

By his second wife Sir James had issue a son : — 4. William, to whom the lands of Whittinghame and Morton were secured, although in 1474 he resigned his rights over Morton in favour of his nephew the first Earl of Morton.3 He was the ancestor of the Douglases of Whittinghame, whose principal male line ended in an heiress Elizabeth, who married Alexander, Viscount of Kingston, in 1661. She was served heir to her brother Archibald Douglas on 15 May 1662. The only one of her children who left issue married William Hay of Drummelzier, and their descendants are the lineal representatives of the Douglases of Whittinghame. (See title Kingston.)

In other words, TSP doesn’t trace the line, at least not in this “Douglas of Morton” article.

https://genealogics.org/getperson.php?personID=I00498082&tree=LEO Shows the younger William married to 1) Euphemia 2) Margaret Fleming.

Here’s the current Cawley article.

https://fmg.ac/Projects/MedLands/SCOTTISH%20NOBILITY%20LATER.htm

He doesn’t list the children of James & his 2nd wife.

b) JAMES Douglas ([1373/74?]-before 22 May 1441). … m secondly as her first husband, JANET Borthwick, daughter of WILLIAM Borthwick of Borthwick & his wife ---. She married secondly George Crichton Earl of Caithness. James & his first wife had three children: …