After 1610 [his father] William Cavendish 1st Duke Newcastle upon Tyne (age 17) and [his mother] Elizabeth Bassett Countess Newcastle upon Tyne (age 18) were married. He a great x 4 grandson of King Edward IV of England.

Before 1616 Henry Howard (age 24) and [his mother] Elizabeth Bassett Countess Newcastle upon Tyne (age 23) were married. He the son of Thomas Howard 1st Earl Suffolk (age 54) and Catherine Knyvet Countess Suffolk (age 51).

In 1645 [his father] William Cavendish 1st Duke Newcastle upon Tyne (age 52) and [his step-mother] Margaret Lucas Duchess Newcastle upon Tyne (age 22) were married. The difference in their ages was 30 years. They were fourth cousins. He a great x 4 grandson of King Edward IV of England.

In 1652 Henry Cavendish 2nd Duke Newcastle upon Tyne (age 21) and Frances Pierrepont Duchess Newcastle upon Tyne (age 21) were married. He the son of William Cavendish 1st Duke Newcastle upon Tyne (age 59) and Elizabeth Bassett Countess Newcastle upon Tyne. They were second cousin once removed. He a great x 5 grandson of King Edward IV of England.

On 30 Dec 1669 [his son-in-law] Christopher Monck 2nd Duke Albemarle (age 16) and [his daughter] Elizabeth "Mad Duchess" Cavendish Duchess Albermarle Duchess Montagu (age 15) were married at Whitehall Palace [Map]. She the daughter of Henry Cavendish 2nd Duke Newcastle upon Tyne (age 39) and Frances Pierrepont Duchess Newcastle upon Tyne (age 39). He the son of George Monck 1st Duke Albemarle (age 61) and Anne Clarges Duchess Albermarle (age 50). He a great x 4 grandson of King Edward IV of England.

On 27 Mar 1679 [his son] Henry Cavendish (age 20) and [his daughter-in-law] 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).

In 1680 [his brother-in-law] Gervase Pierrepont 1st Baron Pierrepont (age 31) and Lucy Pelham Baroness Pierrepont Hanslape Buckingham were married.

On 14 Aug 1684 [his son-in-law] Thomas Tufton 6th Earl of Thanet (age 39) and [his daughter] Catherine Cavendish Countess Isle Thanet (age 19) were married. She by marriage Countess of Thanet. The difference in their ages was 20 years. She the daughter of Henry Cavendish 2nd Duke Newcastle upon Tyne (age 54) and Frances Pierrepont Duchess Newcastle upon Tyne (age 53). He the son of John Tufton 2nd Earl of Thanet and Margaret Sackville Countess Isle Thanet.

In 1685 [his son-in-law] John Campbell 2nd Earl Breadalbaine and Holland (age 22) and [his daughter] Frances Cavendish (age 24) were married. She the daughter of Henry Cavendish 2nd Duke Newcastle upon Tyne (age 54) and Frances Pierrepont Duchess Newcastle upon Tyne (age 54). He the son of John Campbell 1st Earl Breadalbaine and Holland (age 48) and Mary Rich.

On 01 Mar 1690 [his son-in-law] John Holles 1st Duke Newcastle upon Tyne (age 28) and [his daughter] Margaret Cavendish Duchess Newcastle upon Tyne (age 28) were married. She by marriage Countess Clare. She the daughter of Henry Cavendish 2nd Duke Newcastle upon Tyne (age 59) and Frances Pierrepont Duchess Newcastle upon Tyne (age 59). He the son of Gilbert Holles 3rd Earl de Clare and Grace Pierrepont Countess de Clare (age 57). They were first cousins.

On 08 Sep 1692 Ralph Montagu 1st Duke Montagu (age 53) and [his daughter] Elizabeth "Mad Duchess" Cavendish Duchess Albermarle Duchess Montagu (age 38) were married at Newcastle House. She the daughter of Henry Cavendish 2nd Duke Newcastle upon Tyne who had died the year before and the widow of [his former son-in-law] Christopher Monck 2nd Duke Albemarle. She the daughter of Henry Cavendish 2nd Duke Newcastle upon Tyne and Frances Pierrepont Duchess Newcastle upon Tyne (age 62).

In or before 1660 Robert Pierrepont and Elizabeth Evelyn were married.