Mary Stewart Countess Erroll was born to John Stewart 4th Earl Atholl -1579 and Elizabeth Gordon Countess Atholl -1557.
Francis Hay 9th Earl Erroll and Mary Stewart Countess Erroll were married. She by marriage Countess Erroll. She the daughter of John Stewart 4th Earl Atholl -1579 and Elizabeth Gordon Countess Atholl -1557. He the son of Andrew Hay 8th Earl Erroll 1531-1585 and Jean Hay. They were third cousins.
Paternal Family Tree: Stewart
Kings Wessex: Great x 15 Grand Daughter of King Edmund "Ironside" I of England
Kings Gwynedd: Great x 12 Grand Daughter of Owain "Great" King Gwynedd 1100-1170
Kings Seisyllwg: Great x 18 Grand Daughter of Hywel "Dda aka Good" King Seisyllwg King Deheubarth
Kings Powys: Great x 13 Grand Daughter of Maredudd ap Bleddyn King Powys 1047-1132
Kings England: Great x 6 Grand Daughter of King Edward III of England
Kings Scotland: Great x 8 Grand Daughter of Robert "The Bruce" I King Scotland
Kings Franks: Great x 12 Grand Daughter of Louis VII King Franks
Kings France: Great x 8 Grand Daughter of Philip "The Fair" IV King France
Great x 4 Grandfather: John Stewart of Innermeath 3rd of Lorn
Great x 3 Grandfather: James "Black Knight of Lorn" Stewart
Great x 4 Grandmother: Isabel Macdougall
Great x 2 Grandfather: John Stewart 1st Earl Atholl 1440- 2 x Great Grand Son of King Edward III of England
Great x 4 Grandfather: John Beaufort 1st Marquess Somerset and Dorset
Grand Son of King Edward III of England
Great x 3 Grandmother: Joan Beaufort Queen Consort Scotland Great Grand Daughter of King Edward III of England
Great x 4 Grandmother: Margaret Holland Duchess Clarence
2 x Great Grand Daughter of King Edward "Longshanks" I of England
Great x 1 Grandfather: John Stewart 2nd Earl Atholl 1475-1522 3 x Great Grand Son of King Edward III of England
Great x 4 Grandfather: Henry Sinclair 2nd Earl Orkney
Great x 3 Grandfather: William Sinclair 3rd Earl Orkney 1st Earl Caithness 6 x Great Grand Son of King John "Lackland" of England
Great x 4 Grandmother: Egidia "Fair Maid of Nithsdale" Douglas Countess Orkney 1380-1438 5 x Great Grand Daughter of King John "Lackland" of England
Great x 2 Grandmother: Eleanor Sinclair Countess Atholl 1457-1518 7 x Great Grand Daughter of King John "Lackland" of England
GrandFather: John Stewart 3rd Earl Atholl 1507-1542 4 x Great Grand Son of King Edward III of England
Great x 4 Grandfather: Archibald Campbell 6 x Great Grand Son of King John "Lackland" of England
Great x 3 Grandfather: Colin Campbell 1st Earl Argyll 7 x Great Grand Son of King John "Lackland" of England
Great x 2 Grandfather: Archibald Campbell 2nd Earl Argyll 1449-1513 8 x Great Grand Son of King John "Lackland" of England
Great x 4 Grandfather: John Stewart 2nd Lord Lorn 6 x Great Grand Son of King John "Lackland" of England
Great x 3 Grandmother: Isabella Stewart Countess Argyll 7 x Great Grand Daughter of King John "Lackland" of England
Great x 1 Grandmother: Janet Campbell Countess Atholl 9 x Great Grand Daughter of King John "Lackland" of England
Great x 4 Grandfather: Alan Stewart of Darnley
Great x 3 Grandfather: John Stewart 1st Earl Lennox 1429-1495 13 x Great Grand Son of King Henry I "Beauclerc" England
Great x 4 Grandmother: Catherine Seton 12 x Great Grand Daughter of King Henry I "Beauclerc" England
Great x 2 Grandmother: Elizabeth Stewart Countess Argyll 1463- 14 x Great Grand Daughter of King Henry I "Beauclerc" England
Great x 4 Grandfather: Alexander Montgomerie 1st Lord Montgomerie
Great x 3 Grandmother: Margaret Montgomerie Countess Lennox
Great x 4 Grandmother: Margaret Boyd
Father: John Stewart 4th Earl Atholl -1579 5 x Great Grand Son of King Edward III of England
Mary Stewart Countess Erroll 6 x Great Grand Daughter of King Edward III of England
Great x 4 Grandfather: Alexander Gordon 1st Earl Huntley 12 x Great Grand Son of King Henry I "Beauclerc" England
Great x 3 Grandfather: George Gordon 2nd Earl Huntley 13 x Great Grand Son of King Henry I "Beauclerc" England
Great x 2 Grandfather: Alexander Gordon 3rd Earl Huntley -1524 14 x Great Grand Son of King Henry I "Beauclerc" England
Great x 1 Grandfather: John Gordon 4 x Great Grand Son of King Edward III of England
Great x 4 Grandfather: James "Black Knight of Lorn" Stewart
Great x 3 Grandfather: John Stewart 1st Earl Atholl 1440- 2 x Great Grand Son of King Edward III of England
Great x 4 Grandmother: Joan Beaufort Queen Consort Scotland Great Grand Daughter of King Edward III of England
Great x 2 Grandmother: Jean Stewart Countess Huntley 1461-1510 3 x Great Grand Daughter of King Edward III of England
Great x 4 Grandfather: William Sinclair 3rd Earl Orkney 1st Earl Caithness 6 x Great Grand Son of King John "Lackland" of England
Great x 3 Grandmother: Eleanor Sinclair Countess Atholl 1457-1518 7 x Great Grand Daughter of King John "Lackland" of England
GrandFather: George Gordon 4th Earl Huntley 1514-1562 5 x Great Grand Son of King Edward III of England
Great x 4 Grandfather: King James II of Scotland
2 x Great Grand Son of King Edward III of England
Great x 3 Grandfather: King James III of Scotland 3 x Great Grand Son of King Edward III of England
Great x 4 Grandmother: Mary of Guelders Queen Consort Scotland 1434-1463 6 x Great Grand Daughter of King Edward "Longshanks" I of England
Great x 2 Grandfather: King James IV of Scotland 4 x Great Grand Son of King Edward III of England
Great x 4 Grandfather: Christian I King Denmark 1426-1481
Great x 3 Grandmother: Margaret Oldenburg Queen Consort Scotland 1456-1486
Great x 4 Grandmother: Dorothea of Brandenburg
Great x 1 Grandmother: Margaret Stewart 5 x Great Grand Daughter of King Edward III of England
Great x 3 Grandfather: John Drummond 1st Lord Drummond
Great x 2 Grandmother: Margaret Drummond 9 x Great Grand Daughter of King John "Lackland" of England
Great x 4 Grandfather: Tiger Earl 4th Earl Crawford 7 x Great Grand Son of King John "Lackland" of England
Great x 3 Grandmother: Elizabeth Lindsay Lady Drummond 8 x Great Grand Daughter of King John "Lackland" of England
Great x 4 Grandmother: Margaret Dunbar Countess Crawford 1425-1499
12 x Great Grand Daughter of King Henry I "Beauclerc" England
Mother: Elizabeth Gordon Countess Atholl -1557 6 x Great Grand Daughter of King Edward III of England