Around 1222 Matilda Angus 6th Countess Angus was born to Maol Choluim Angus 5th Earl Angus [aged 32].
In 1242 [her father] Maol Choluim Angus 5th Earl Angus [aged 52] died. His succeeded daughter Matilda [aged 20] succeeded 6th Countess Angus.
In 1245 [her son] Gilbert Umfraville 7th Earl Angus was born to Gilbert Umfraville [aged 50] and Matilda Angus 6th Countess Angus [aged 23]. He married before 1277 his fourth cousin Elisabetha Comyn, daughter of Alexander Comyn 2nd Earl Buchan and Elizabeth Quincy Countess Buchan, and had issue.
Before 12th December 1247 Richard de Dover Plantagenet [aged 27] and Matilda Angus 6th Countess Angus [aged 25] were married. She the daughter of Maol Choluim Angus 5th Earl Angus. They were fourth cousins. He a grandson of King John of England.
In 1261 Matilda Angus 6th Countess Angus [aged 39] died. Her succeeded son Gilbert Umfraville 7th Earl Angus [aged 16] succeeded 7th Earl Angus.
On 9th August 1270 [her former husband] Richard de Dover Plantagenet [aged 50] died in Carthage.
Gilbert Umfraville and Matilda Angus 6th Countess Angus were married. The difference in their ages was 27 years. She the daughter of Maol Choluim Angus 5th Earl Angus.
John Comyn Earl Angus and Matilda Angus 6th Countess Angus were married. She the daughter of Maol Choluim Angus 5th Earl Angus. He the son of William Comyn Earl Buchan and Sarah Fitzhugh.
[her daughter] Isabel Plantagenet Countess of Atholl was born to Richard de Dover Plantagenet and Matilda Angus 6th Countess Angus. She a great granddaughter of King John of England. She married before June 1266 David Strathbogie 8th Earl Atholl and had issue.
William of Worcester's Chronicle of England
William of Worcester, born around 1415, and died around 1482 was secretary to John Fastolf, the renowned soldier of the Hundred Years War, during which time he collected documents, letters, and wrote a record of events. Following their return to England in 1440 William was witness to major events. Twice in his chronicle he uses the first person: 1. when writing about the murder of Thomas, 7th Baron Scales, in 1460, he writes '… and I saw him lying naked in the cemetery near the porch of the church of St. Mary Overie in Southwark …' and 2. describing King Edward IV's entry into London in 1461 he writes '… proclaimed that all the people themselves were to recognize and acknowledge Edward as king. I was present and heard this, and immediately went down with them into the city'. William’s Chronicle is rich in detail. It is the source of much information about the Wars of the Roses, including the term 'Diabolical Marriage' to describe the marriage of Queen Elizabeth Woodville’s brother John’s marriage to Katherine, Dowager Duchess of Norfolk, he aged twenty, she sixty-five or more, and the story about a paper crown being placed in mockery on the severed head of Richard, 3rd Duke of York.
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[her son] Richard Plantagenet was born to Richard de Dover Plantagenet and Matilda Angus 6th Countess Angus. He a great grandson of King John of England.
Kings Wessex: Great x 6 Grand Daughter of King Edmund "Ironside" I of England
Kings Scotland: Great x 3 Grand Daughter of King David I of Scotland
Kings France: Great x 7 Grand Daughter of Hugh I King of the Franks
Kings Duke Aquitaine: Great x 11 Grand Daughter of Ranulf I Duke Aquitaine
Great x 1 Grandfather: Gille Críst Angus 4th Earl Angus
GrandFather: Donnchad Angus 5th Earl Angus Great Grand Son of King David I of Scotland
Great x 4 Grandfather: King Malcolm III of Scotland 
Son of King Duncan I of Scotland
Great x 3 Grandfather: King David I of Scotland Son of King Malcolm III of Scotland
Great x 4 Grandmother: Margaret Wessex Queen Consort Scotland Grand Daughter of King Edmund "Ironside" I of England
Great x 2 Grandfather: Henry Dunkeld 3rd Earl Huntingdon 1st Earl of Northumbria Son of King David I of Scotland
Great x 4 Grandfather: Waltheof Northumbria 1st Earl of Northampton 1st Earl Huntingdon
Great x 3 Grandmother: Maud Queen Consort Scotland 6 x Great Grand Daughter of King Edward "Elder" of the Anglo Saxons
Great x 4 Grandmother: Judith Flanders Countess Huntingdon 5 x Great Grand Daughter of King Edward "Elder" of the Anglo Saxons
Great x 1 Grandmother: Marjorie Dunkeld Countess Angus Grand Daughter of King David I of Scotland
Great x 4 Grandfather: William Warenne 1st Earl of Surrey 
Great x 3 Grandfather: William Warenne 2nd Earl of Surrey
Great x 4 Grandmother: Gundred Countess of Surrey
Great x 2 Grandmother: Ada Warenne Countess Huntingdon and Northumbria 3 x Great Grand Daughter of Hugh I King of the Franks
Great x 4 Grandfather: Hugh "Great" Capet 
Great Grand Son of Hugh I King of the Franks
Great x 3 Grandmother: Elizabeth Capet Countess Leicester, Meulan and Surrey 2 x Great Grand Daughter of Hugh I King of the Franks
Great x 4 Grandmother: Adelaide I Countess Vermandois 8 x Great Grand Daughter of Charles "Charlemagne aka Great" King of the Franks King Lombardy Holy Roman Emperor
Father: Maol Choluim Angus 5th Earl Angus 2 x Great Grand Son of King David I of Scotland
Matilda Angus 6th Countess Angus 3 x Great Grand Daughter of King David I of Scotland