On 28 Sep 1361 [his father] Robert Stewart 1st Duke Albany (age 21) and Margaret Graham Countess Menteith and Fife (age 27) were married. He by marriage Earl Menteith. She the daughter of John Graham Earl Menteith and Margaret Graham 2nd Countess Menteith and Mar. He the son of King Robert II of Scotland (age 45) and Elizabeth Mure Queen Consort Scotland. He a great x 4 grandson of King John "Lackland" of England.

In 1381 [his father] Robert Stewart 1st Duke Albany (age 41) and [his mother] Muriella Keith Duchess Albany (age 23) were married. He the son of King Robert II of Scotland (age 64) and Elizabeth Mure Queen Consort Scotland. He a great x 4 grandson of King John "Lackland" of England.

In 1390 John Stewart 2nd Earl Buchan (age 9) and Elizabeth Douglas Countess Buchan and Orkney and Caithness were married. She the daughter of Archibald Douglas 1st Duke Touraine (age 18) and Margaret Stewart Duchess Touraine. He the son of Robert Stewart 1st Duke Albany (age 50) and Muriella Keith Duchess Albany (age 32). They were first cousin once removed. He a great x 5 grandson of King John "Lackland" of England.

Around 01 May 1427 Thomas Stewart and [his former wife] Elizabeth Douglas Countess Buchan and Orkney and Caithness were married. She the daughter of Archibald Douglas 1st Duke Touraine and Margaret Stewart Duchess Touraine. He the son of Alexander Stewart 1st Earl Mar (age 52). They were second cousins.

William Sinclair 3rd Earl Orkney 1st Earl Caithness and Elizabeth Douglas Countess Buchan and Orkney and Caithness were married. She by marriage Countess Orkney. She the daughter of Archibald Douglas 1st Duke Touraine and Margaret Stewart Duchess Touraine. He the son of Henry Sinclair 2nd Earl Orkney and Egidia "Fair Maid of Nithsdale" Douglas Countess Orkney. They were half first cousin once removed.

Thomas son Alexander Earl Mar and Elizabeth Douglas Countess Buchan and Orkney and Caithness were married. She the daughter of Archibald Douglas 1st Duke Touraine and Margaret Stewart Duchess Touraine.