On 04 Aug 1632 [his father] Charles Seymour 2nd Baron Seymour Trowbridge (age 11) and Mary Smith (age 11) were married. They had one son and two daughters He a great x 4 grandson of King Henry VII of England and Ireland.

In 1654 [his father] Charles Seymour 2nd Baron Seymour Trowbridge (age 33) and [his mother] Eizabeth Alington 2nd Baroness Seymour Trowbridge (age 18) were married. She by marriage Baroness Seymour Trowbridge. They had five sons and two daughters. They were fourth cousins. He a great x 4 grandson of King Henry VII of England and Ireland.

On 27 Mar 1679 Henry Cavendish (age 20) and [his future wife] Elizabeth Percy Duchess Somerset (age 12) were married. She being the sole heiress of Josceline Percy 11th Earl of Northumberland she brought an enormous fortune to the marriage. She the daughter of Josceline Percy 11th Earl of Northumberland and Elizabeth Wriothesley Countess Northumberland (age 33). He the son of Henry Cavendish 2nd Duke Newcastle upon Tyne (age 48) and Frances Pierrepont Duchess Newcastle upon Tyne (age 48).

On 15 Nov 1681 Thomas "Tom of Ten Thousand" Thynne (age 33) and [his future wife] Elizabeth Percy Duchess Somerset (age 14) were married. She the daughter of Josceline Percy 11th Earl of Northumberland and Elizabeth Wriothesley Countess Northumberland (age 35).

On 30 May 1682 Charles Seymour 6th Duke Somerset (age 19) and Elizabeth Percy Duchess Somerset (age 15) were married. His first marriage, her third having been widowed twice by the age of seventeen. She by marriage Duchess Somerset. Being the sole heiress of her father Josceline Percy 11th Earl of Northumberland she brought considerable wealth to the marriage. She the daughter of Josceline Percy 11th Earl of Northumberland and Elizabeth Wriothesley Countess Northumberland (age 36). He a great x 5 grandson of King Henry VII of England and Ireland.

In 1707 [his son-in-law] Henry O'Brien 8th Earl Thomond (age 18) and [his daughter] Elizabeth Seymour Countess Thomond (age 22) were married. She by marriage Countess Thomond. She the daughter of Charles Seymour 6th Duke Somerset (age 44) and Elizabeth Percy Duchess Somerset (age 39). He the son of Henry Horatio O'Brien and Henrietta Somerset Countess Suffolk (age 38).

Before 19 Aug 1710 [his son-in-law] William Wyndham 3rd Baronet (age 22) and [his daughter] Catherine Seymour (age 17) were married. She the daughter of Charles Seymour 6th Duke Somerset (age 48) and Elizabeth Percy Duchess Somerset (age 43).

On 05 Jul 1715 [his son] Algernon Seymour 7th Duke Somerset (age 30) and [his daughter-in-law] Frances Thynne Duchess Somerset (age 16) were married. He the son of Charles Seymour 6th Duke Somerset (age 52) and Elizabeth Percy Duchess Somerset (age 48). They were third cousin once removed.

On 17 Sep 1719 [his son-in-law] Peregrine Osborne 3rd Duke Leeds (age 27) and [his daughter] Anne Seymour Duchess Leeds (age 10) were married. She the daughter of Charles Seymour 6th Duke Somerset (age 57) and Elizabeth Percy Duchess Somerset (age 52). He the son of Peregrine Osborne 2nd Duke Leeds (age 60) and Bridget Hyde Duchess Leeds (age 57).

On 04 Feb 1725 Charles Seymour 6th Duke Somerset (age 62) and Charlotte Finch Duchess Somerset (age 32) were married. She by marriage Duchess Somerset. The difference in their ages was 30 years. She the daughter of Daniel Finch 2nd Earl Nottingham 7th Earl Winchilsea (age 77) and Anne Hatton Countess Nottingham and Winchelsea. He a great x 5 grandson of King Henry VII of England and Ireland.

On 09 Sep 1746 [his brother-in-law] Edward Finch-Hatton (age 49) and Elizabeth Palmer (age 37) were married. He the son of Daniel Finch 2nd Earl Nottingham 7th Earl Winchilsea and Anne Hatton Countess Nottingham and Winchelsea.