Sir Robert Lord Erskine, 1st Lord Erskine

ROBERT ERSKINE; s. and h. of Sir Thomas E. of that ilk [i.e. Erskine, on the Clyde] (d. between Martinmas [11 Nov.] 1403 and Whitsunday [18 May] 1404), by Janet,1 widow of Sir David Barclay, of Brechin, and probably dau. and h. of Sir Edward Keith, of Syntoun; knighted before 20 Dec.1400; was taken prisoner at the battle of Homildon, 14 Sep. 1402; was one of the hostages for the ransom of King James in 1424, when his revenue was estimated at 1,ooo marks, being set at liberty 19 June 1425. He was made a Lord of Parl.,2 as LORD ERSKINE in or shortly before 1433.3 Soon after the death (1435) of Alexander, husband of Isabel,Countess of Mar (to which Alexander and his heirs by her that Earldom 4 had been resigned), Lord Erskine was served h. to the said Countess Isabel, and having had seizin 21 Nov. 1438, assumed the title of EARL OF MAR. He m., soon after 20 Dec. 1400,5 Elizabeth, dau. of David (LINDSAY), 1st EARL OF CRAWFORD, by Elizabeth, dau. of ROBERT II. He d. between 7 Sept. 1451 and 6 Nov. 1452.

http://www.erskinclan.com/gene4.html

Father of Thomas Erskine, 2nd Lord Erskine (d. 1494)

http://en.wikipedia.org/wiki/Thomas_Erskine,_2nd_Lord_Erskine