The Erskines' claim to the Earldom of Mar
As we have already seen, Alexander Stewart (~1375 – 1435) was a thoroughly nasty piece of work. He was a (natural) son of Alexander Stewart, Earl of Buchan (the infamous Wolf of Badenoch) and only held the Earldom of Mar and the Lordship of the Garioch by force majeure, following marriage to his first wife Isabel Douglas, Countess of Mar (d 1408) after his capture of Kildrummy Castle, and Isabel with it, in 1404. This event sent major shockwaves throughout the kingdom and Alexander only escaped punishment because he was a close relation of the Royal Family. But his possession of the Earldom was later regularised in 1424 by grant of his cousin, King James I. This was effectively a second creation of the earldom.
Stewart died without legitimate issue, however, and the rules of inheritance had therefore to be consulted. He himself had claimed the title through his wife Isabel, the Countess of Mar. Now the first Lord Erskine, Sir Robert Erskine, claimed the title through his descent from an earlier Countess of Mar, Christina Bruce, Lady of Garioch, wife of Gratnait the 7th Earl.
The justice of this claim can be seen from the Generation Table shown below, though the descent is entirely through the female line. But Erskine's claim was refused by the king who said that the title belonged to the crown because the last male holder had been a Stewart.
Justice had to wait a while.
| # | Individual | Spouse / Partner | Family |
| Christina Bruce, Lady of Garioch, Countess of Mar (d 1356/7) sister of Robert Bruce, King of Scotland |
Gartnait, 8th Earl of Mar (m ~1292) son of Donald, 7th Earl of Mar & Helen ferch Llywelyn (daughter of Daffyd ap Llywelyn, Prince of North Wales) |
Helen (Ellen) of Mar (d >1342) Donald, 8th Earl of Mar (b <1305, d 12 Aug 1332) | |
| Sir Christopher Seton of that Ilk (m 1305/6) |
Margaret Seton | ||
| Sir Andrew Moray of Bothwell (m >12 Oct 1325) |
Sir John Moray, Lord of Bothwell (d 1352) Sir Thomas Moray, Lord of Bothwell (d 1361) | ||
| Helen (Ellen) of Mar (d >1342) |
Sir John Menteith, Lord of Arran |
Sir John Menteith of Strathgartney (d ~6 Aug 1363) Christian Menteith (d ~ 1387) Unknown daughter | |
| Sir James Garioch | Sir Andrew Garioch of Caskieben | ||
| Christian Menteith (d ~1387) |
Sir Edward Keith of Synton
(d 17 Oct 1346, Battle of Neville's Cross) |
Janet Keith | |
| Sir Robert Erskine of that Ilk (m 1352) |
|||
| Janet Keith | Sir David Barclay of Brechin (m <1368) |
Margaret Barclay (d <1 Aug 1404) | |
| Sir Thomas Erskine of that Ilk (m ~ 13 Apr 1370) |
Sir Robert Erskine of that Ilk, 1st Lord Erskine (d 7 Sep 1451 – 6 Nov 1452) John Erskine of Dun daughter |
We see that Helen of Mar was not only the daughter of an Earl of Mar but also the sister of another. And not only was her direct descendant Christian Menteith married to an Erskine, but so was her daughter Janet – and indeed the mother of one too! The Mars and the Erskines were practically joined at the hip.