Margaret o Mar (died c. 1391) wis Coontess o Mar frae 1374 tae 1391, an auncient Earldom in Scotland, in her awn richt.
She wis a dochter o Domhnall II o Mar an efter the daith o her childless brither Thomas became Coontess o Mar. She haed marriet William Douglas, 1st Earl o Douglas, who wis succeedit bi thair son, James Douglas, 2nt Earl o Douglas an Earl o Mar an Garioch in right o his mither, an whan he fell, leadin the Scots at the battle o Otterburn.
She wis succeedit bi her dochter, Isabel, who became Coontess o Mar, possessed the Lairdship o the Garioch, an an aw became the Coontesss o the unentailed lands o the Hoose o Douglas.
| Precedit bi Thomas |
Coontess o Mar 1374–1391 |
Succeedit bi Isabella |