On 06 Jul 1833 [his father] Albert Denison 1st Baron Londesborough (age 27) and [his mother] Henrietta Maria Weld-Forester Baroness Londesborough were married. He the son of Henry Conyngham 1st Marquess Conyngham and Elizabeth Denison Marchioness Conyngham (age 64).

On 29 Dec 1836 Christopher William Codrington (age 31) and [his future sister-in-law] Georgiana Charlotte Anne Somerset (age 19) were married. She the daughter of Henry Somerset 7th Duke Beaufort (age 44) and Georgiana Frederica Fitzroy. They were third cousin once removed. He a great x 4 grandson of King Charles II of England Scotland and Ireland. She a great x 5 granddaughter of King Charles II of England Scotland and Ireland.

On 21 Dec 1847 [his father] Albert Denison 1st Baron Londesborough (age 42) and [his step-mother] Ursula Lucy Grace Bridgeman (age 24) were married. He the son of Henry Conyngham 1st Marquess Conyngham and Elizabeth Denison Marchioness Conyngham (age 78).

On 20 Jul 1858 Arthur Walsh 2nd Baron Ormathwaite (age 31) and [his future sister-in-law] Katherine Somerset Baroness Ormathwaite (age 23) were married. She the daughter of Henry Somerset 7th Duke Beaufort and Emily Frances Smith Duchess Beaufort (age 58).

In 1863 William Henry Forester Denison 1st Earl Londesborough (age 28) and Edith Somerset Countess Londesborough (age 24) were married. She by marriage Baroness Londesborough of Londesborough in the East Riding of Yorkshire. She the daughter of Henry Somerset 7th Duke Beaufort and Emily Frances Smith Duchess Beaufort (age 62). They were third cousins.

In 1886 [his son-in-law] George Reresby Sitwell 4th Baronet (age 25) and [his daughter] Ida Emily Augusta Denison Lady Sitwell (age 17) were married. She by marriage Lady Sitwell of Renishaw Hall in Derbyshire. She the daughter of William Henry Forester Denison 1st Earl Londesborough (age 51) and Edith Somerset Countess Londesborough (age 47).

On 03 Feb 1887 [his son-in-law] Gerald William Henry Codrington 1st Baronet (age 37) and [his daughter] Edith Henrietta Sybil Denison Lady Codrington (age 22) were married. She by marriage Lady Codrington of Dodington. She the daughter of William Henry Forester Denison 1st Earl Londesborough (age 52) and Edith Somerset Countess Londesborough (age 48). They were half first cousins. He a great x 5 grandson of King Charles II of England Scotland and Ireland.

On 11 Aug 1887 [his son] William Henry Francis Denison 2nd Earl Londesborough (age 23) and [his daughter-in-law] Grace Adelaide Fane Countess Londesborough (age 26) were married. She the daughter of Francis William Henry Fane 12th Earl of Westmoreland (age 61) and Adelaide Ida Curzon Howe Countess of Westmoreland (age 52). He the son of William Henry Forester Denison 1st Earl Londesborough (age 53) and Edith Somerset Countess Londesborough (age 49). They were third cousins.