Before 1424 James "Gross" Douglas 7th Earl Douglas 1st Earl Avondale (age 53) and Beatrice Stewart Countess Douglas and Avondale (age 62) were married. She by marriage Countess Douglas, Countess Avondale. She the daughter of Robert Stewart 1st Duke Albany and Margaret Graham Countess Menteith and Fife. He the son of Archibald "Grim" Douglas 3rd Earl Douglas and Joanna Strathearn Countess Douglas. They were half third cousin once removed. She a great x 5 granddaughter of King John "Lackland" of England.

Before 1455 James Douglas 9th Earl Douglas 3rd Earl Avondale (age 29) and Margaret "Fair Lady of Galloway" Douglas Countess (age 19) were married. She by marriage Countess Douglas, Countess Avondale. She had previously married his brother William Douglas 8th Earl Douglas 2nd Earl Avondale; an example of Married to Two Siblings. She the daughter of Archibald Douglas 2nd Duke Touraine and Euphemia Graham Lady Hamilton (age 46). He the son of James "Gross" Douglas 7th Earl Douglas 1st Earl Avondale and Beatrix Sinclair Countess Douglas and Avondale (age 56). They were first cousin once removed.

After 1463 James Douglas 9th Earl Douglas 3rd Earl Avondale (age 37) and Anne Holland Countess Douglas and Avondale were married. She by marriage Countess Douglas, Countess Avondale. She the daughter of John Holland 2nd Duke Exeter and Anne Stafford Duchess Exeter. He the son of James "Gross" Douglas 7th Earl Douglas 1st Earl Avondale and Beatrix Sinclair Countess Douglas and Avondale. She a great x 2 granddaughter of King Edward III of England.

After 1464 James "Gross" Douglas 7th Earl Douglas 1st Earl Avondale and Beatrix Sinclair Countess Douglas and Avondale were married. She by marriage Countess Douglas, Countess Avondale. The difference in their ages was 27 years. She the daughter of Henry Sinclair 2nd Earl Orkney and Egidia "Fair Maid of Nithsdale" Douglas Countess Orkney. He the son of Archibald "Grim" Douglas 3rd Earl Douglas and Joanna Strathearn Countess Douglas. They were great uncle and niece.

James Douglas 2nd Earl Douglas and Isabella Stewart Countess Douglas were married. She by marriage Countess Douglas. She the daughter of King Robert II of Scotland and Elizabeth Mure Queen Consort Scotland. He the son of William Douglas 1st Earl Douglas and Margaret Mar Countess Douglas 11th Countess Mar. They were half third cousin once removed. She a great x 4 granddaughter of King John "Lackland" of England.