On 22 Jun 1610 William Seymour 2nd Duke Somerset (age 22) and Arabella Stewart (age 35) were married in secret at Palace of Placentia, Greenwich [Map]. For having married without permission King James I of England and Ireland and VI of Scotland (age 44) had Arabella Stewart (age 35) imprisoned in Sir Thomas Perry's House Lambeth, Surrey and he in the Tower of London [Map]. She the daughter of Charles Stewart 5th Earl Lennox and Elizabeth Cavendish Countess Lennox. They were third cousin once removed. He a great x 3 grandson of King Henry VII of England and Ireland. She a great x 2 granddaughter of King Henry VII of England and Ireland.

On 03 Mar 1617 William Seymour 2nd Duke Somerset (age 29) and Frances Devereux Duchess of Somerset (age 17) were married at Drayton Bassett, Staffordshire [Map]. She the daughter of Robert Devereux 2nd Earl Essex and Frances Walsingham Countess Essex (age 50). They were fourth cousins. He a great x 3 grandson of King Henry VII of England and Ireland.

Before 09 Sep 1623 Henry Shirley 2nd Baronet (age 35) and [his sister-in-law] Dorothy Devereux Lady Shirley (age 23) were married. She the daughter of Robert Devereux 2nd Earl Essex and Frances Walsingham Countess Essex (age 56).

Around 1637 [his son-in-law] Richard Molyneux 2nd Viscount Molyneux (age 18) and [his daughter] Frances Seymour Countess Southampton (age 19) were married. She by marriage Viscountess Molyneux. She the daughter of William Seymour 2nd Duke Somerset (age 49) and Frances Devereux Duchess of Somerset (age 37). She a great x 4 granddaughter of King Henry VII of England and Ireland.

On 28 Jun 1648 [his son] Henry Seymour (age 22) and [his daughter-in-law] Mary Capell Duchess Beaufort (age 17) were married at Little Hadham, Hertfordshire [Map]. He the son of William Seymour 2nd Duke Somerset (age 60) and Frances Devereux Duchess of Somerset (age 48). They were fourth cousins. He a great x 4 grandson of King Henry VII of England and Ireland.

Around 1650 [his son-in-law] Heneage Finch 3rd Earl Winchilsea (age 22) and [his daughter] Mary Seymour Countess Winchelsea (age 13) were married. She by marriage Countess Winchilsea. She the daughter of William Seymour 2nd Duke Somerset (age 62) and Frances Devereux Duchess of Somerset (age 50). He the son of Thomas Finch 2nd Earl Winchilsea and Cecily Wentworth Countess Winchelsea. They were third cousins. She a great x 4 granddaughter of King Henry VII of England and Ireland.

In 1656 [his son] John Seymour 4th Duke Somerset (age 11) and [his daughter-in-law] Sarah Alston Duchess Somerset (age 14) were married. He the son of William Seymour 2nd Duke Somerset (age 68) and Frances Devereux Duchess of Somerset (age 56). He a great x 4 grandson of King Henry VII of England and Ireland.

On 07 May 1659 [his son-in-law] Thomas Wriothesley 4th Earl of Southampton 2nd Earl Chichester (age 52) and [his daughter] Frances Seymour Countess Southampton (age 41) were married. She by marriage Countess of Southampton. She the daughter of William Seymour 2nd Duke Somerset (age 71) and Frances Devereux Duchess of Somerset (age 59). He the son of Henry Wriothesley 3rd Earl of Southampton and Elizabeth Vernon Countess Southampton. She a great x 4 granddaughter of King Henry VII of England and Ireland.

[his father] Edward Seymour and [his mother] Honora Rogers were married. He the son of Edward Seymour 1st Earl Hertford and Catherine Grey Countess Hertford. He a great x 2 grandson of King Henry VII of England and Ireland.