On 14 Oct 1616 [his father] Conyers Darcy 1st Earl Holderness (age 17) and [his mother] Grace Rokeby Countess Holderness (age 16) were married.

On 14 Feb 1631 John Cope 3rd Baronet (age 22) and [his future sister-in-law] Elizabeth Fane (age 23) were married. She the daughter of Francis Fane 1st Earl of Westmoreland and Mary Mildmay Countess of Westmoreland (age 49). They were fourth cousins.

In 1636 [his future brother-in-law] Francis Fane (age 25) and Elizabeth West Baroness Darcy (age 55) were married. The difference in their ages was 30 years; she, unusually, being older than him. He the son of Francis Fane 1st Earl of Westmoreland and Mary Mildmay Countess of Westmoreland (age 54).

Around 1637 Richard Molyneux 2nd Viscount Molyneux (age 18) and [his future wife] 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.

After 13 Oct 1638 William Cope (age 26) and [his future sister-in-law] Elizabeth Fane (age 30) were married. She the daughter of Francis Fane 1st Earl of Westmoreland and Mary Mildmay Countess of Westmoreland (age 56).

On 07 Jul 1648 [his future brother-in-law] Henry Howard (age 28) and Elizabeth Spencer Baroness Craven (age 31) were married. He the son of Thomas Howard 1st Earl Berkshire (age 60) and Elizabeth Cecil Countess Berkshire (age 52). They were fourth cousins.

On 04 Apr 1649 [his future brother-in-law] William Howard (age 27) and Elizabeth Dundas (age 23) were married. He the son of Thomas Howard 1st Earl Berkshire (age 61) and Elizabeth Cecil Countess Berkshire (age 53).

Before Aug 1649 Conyers Darcy 2nd Earl Holderness (age 27) and Catherine Fane (age 24) were married. She the daughter of Francis Fane 1st Earl of Westmoreland and Mary Mildmay Countess of Westmoreland. He the son of Conyers Darcy 1st Earl Holderness (age 50) and Grace Rokeby Countess Holderness (age 49).

On 08 Feb 1650 Conyers Darcy 2nd Earl Holderness (age 28) and Frances Howard (age 23) were married. She the daughter of Thomas Howard 1st Earl Berkshire (age 62) and Elizabeth Cecil Countess Berkshire (age 54). He the son of Conyers Darcy 1st Earl Holderness (age 51) and Grace Rokeby Countess Holderness (age 50).

On 07 May 1659 Thomas Wriothesley 4th Earl of Southampton 2nd Earl Chichester (age 52) and [his future wife] 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.

On 07 May 1661 Charles Boyle 3rd Baron Clifford (age 21) and [his future sister-in-law] Jane Seymour Baroness Clifford (age 24) were married. She the daughter of William Seymour 2nd Duke Somerset and Frances Devereux Duchess of Somerset (age 61). He the son of Richard Boyle 2nd Earl Cork 1st Earl Burlington (age 48) and Elizabeth Clifford Countess Burlington (age 47). She a great x 4 granddaughter of King Henry VII of England and Ireland.

In 1662 Thomas Culpepper (age 24) and [his future sister-in-law] Frances Freschville (age 24) were married. They were third cousin once removed.

On 01 Dec 1663 John Dryden (age 32) and [his sister-in-law] Elizabeth Howard (age 25) were married. She the daughter of Thomas Howard 1st Earl Berkshire (age 76) and Elizabeth Cecil Countess Berkshire (age 67).

After 1665 [his brother-in-law] Robert Howard (age 38) and Honora O'Brien were married. She the daughter of Henry O'Brien 5th Earl Thomond and Mary Brereton Countess Thomond. He the son of Thomas Howard 1st Earl Berkshire (age 77) and Elizabeth Cecil Countess Berkshire (age 69).

In 1676 Conyers Darcy 2nd Earl Holderness (age 54) and Frances Seymour Countess Southampton (age 58) were married. She the daughter of William Seymour 2nd Duke Somerset and Frances Devereux Duchess of Somerset. He the son of Conyers Darcy 1st Earl Holderness (age 76) and Grace Rokeby Countess Holderness. She a great x 4 granddaughter of King Henry VII of England and Ireland.

Before 1679 [his former brother-in-law] Philip Howard (age 49) and Mary Jennings (age 37) were married. He the son of Thomas Howard 1st Earl Berkshire and Elizabeth Cecil Countess Berkshire.

Before 24 Nov 1681 [his son] John Darcy (age 22) and [his daughter-in-law] Bridget Sutton (age 16) were married. He the son of Conyers Darcy 2nd Earl Holderness (age 59) and Frances Howard.

On 08 Jan 1685 Conyers Darcy 2nd Earl Holderness (age 63) and Elizabeth Freschville Countess Holderness (age 51) were married. He the son of Conyers Darcy 1st Earl Holderness (age 85) and Grace Rokeby Countess Holderness.