On 16 Jun 1407 John IV Count Armagnac (age 10) and Blanche Montfort Countess Armagnac (age 10) were married. She the daughter of John Montfort V Duke Brittany and Joanna of Navarre Queen Consort England (age 37). He the son of Bernard VII Count Armagnac (age 44) and Bonne Valois Countess Armagnac and Savoy (age 42). They were second cousins. She a great x 3 granddaughter of King Henry III of England.

On 26 Jul 1407 Alan IX Viscount Rohan (age 25) and [his sister-in-law] Marguerite Montfort Viscountess Rohan (age 15) were married. She the daughter of John Montfort V Duke Brittany and Joanna of Navarre Queen Consort England (age 37). She a great x 3 granddaughter of King Henry III of England.

On 10 May 1419 John IV Count Armagnac (age 22) and Isabella Évreux Countess Armagnac (age 24) were married. She by marriage Countess Armagnac. She the daughter of Charles III King Navarre (age 58) and Eleanor of Castile Queen Consort Navarre (age 56). He the son of Bernard VII Count Armagnac and Bonne Valois Countess Armagnac and Savoy (age 54). They were second cousins. She a great x 5 granddaughter of King Henry III of England.

In 1423 [his former brother-in-law] Richard Montfort (age 28) and Margaret Valois (age 16) were married. She the daughter of Louis Valois Duke Touraine I Duke Orléans and Valentina Visconti. He the son of John Montfort V Duke Brittany and Joanna of Navarre Queen Consort England (age 53). They were second cousins. He a great x 3 grandson of King Henry III of England. She a great x 5 granddaughter of King Henry III of England.

On 10 Oct 1423 [his former brother-in-law] Arthur Montfort III Duke Brittany (age 30) and Margaret Valois (age 29) were married at Dijon. She the daughter of John "Fearless" Valois Duke Burgundy and Margaret Wittelsbach Duchess Burgundy. He the son of John Montfort V Duke Brittany and Joanna of Navarre Queen Consort England (age 53). They were second cousins. He a great x 3 grandson of King Henry III of England. She a great x 4 granddaughter of King Edward "Longshanks" I of England.

In 1437 [his son-in-law] John Valois II Duke Alençon (age 27) and [his daughter] Marie Armagnac Duchess Alençon (age 17) were married. She by marriage Duchess Alençon. She the daughter of John IV Count Armagnac (age 40) and Isabella Évreux Countess Armagnac. He the son of John Valois I Duke Alençon and Marie Montfort Duchess Alençon (age 45). They were second cousins. He a great x 4 grandson of King Henry III of England.

On 29 Aug 1442 [his former brother-in-law] Arthur Montfort III Duke Brittany (age 49) and Jeanne Albret were married at Nérac. He the son of John Montfort V Duke Brittany and Joanna of Navarre Queen Consort England. They were second cousin once removed. He a great x 3 grandson of King Henry III of England.

On 02 Jul 1445 [his former brother-in-law] Arthur Montfort III Duke Brittany (age 51) and Catherine Luxemburg were married. She the daughter of Peter Luxemburg I Count Saint Pol and Margherita Baux (age 51). He the son of John Montfort V Duke Brittany and Joanna of Navarre Queen Consort England. He a great x 3 grandson of King Henry III of England. She a great x 5 granddaughter of King Henry III of England.

[his father] Bernard VII Count Armagnac and [his mother] Bonne Valois Countess Armagnac and Savoy were married. She by marriage Countess Armagnac. She the daughter of John Valois 1st Duke Berry and Joanne Armagnac Duchess Berry. He the son of John II Count Armagnac and Jeanne Countess Armagnac. They were first cousins.

John Montfort V Duke Brittany and Joan Valois Duchess Brittany were married. She by marriage Duchess Brittany 1341 War of Sucession. She the daughter of Charles "Beloved Mad" VI King France and Isabeau Wittelsbach Queen Consort France. He the son of John Montfort V Duke Brittany and Joanna of Navarre Queen Consort England. They were second cousins. He a great x 3 grandson of King Henry III of England. She a great x 5 granddaughter of King Henry III of England.

Amadeus "Red Count" Savoy VII Count Savoy and [his mother] Bonne Valois Countess Armagnac and Savoy were married. She the daughter of John Valois 1st Duke Berry and Joanne Armagnac Duchess Berry. He the son of Amadeus "Green Count" Savoy VI Count Savoy and Bonne Bourbon Countess Savoy.