On 11 Mar 1799 [his father] Thomas Bruce 11th Earl Kincardine 7th Earl Elgin (age 32) and [his mother] Mary Nisbet Countess Elgin (age 20) were married. She by marriage Countess Elgin. They had two sons and three daughters. They divorced before 20 Apr 1808 she having been accused of having an affair with [his step-father] Robert Ferguson of Raith (age 29) whom she subsequently married. The Earl sued Ferguson in both England and Scotland and won £10,000. He the son of Charles Bruce 9th Earl Kincardine 5th Earl Elgin.

On 20 Apr 1808 [his step-father] Robert Ferguson of Raith (age 38) and [his mother] Mary Nisbet Countess Elgin (age 30) were married.

On 21 Sep 1810 [his father] Thomas Bruce 11th Earl Kincardine 7th Earl Elgin (age 44) and [his step-mother] Elizabeth Oswald Countess Kincardine and Elgin (age 20) were married. The difference in their ages was 23 years. He the son of Charles Bruce 9th Earl Kincardine 5th Earl Elgin.

On 22 Apr 1841 James Bruce 12th Earl Kincardine 8th Earl Elgin (age 29) and Elizabeth Mary Cumming Bruce Countess Kincardine and Elgin were married. He the son of Thomas Bruce 11th Earl Kincardine 7th Earl Elgin (age 74) and Mary Nisbet Countess Elgin (age 63).

On 07 Nov 1846 James Bruce 12th Earl Kincardine 8th Earl Elgin (age 35) and Mary Louisa Lambton Countess Kincardine and Elgin (age 27) were married. She by marriage Countess Kincardine, Countess Elgin. She the daughter of John "Radical Jack" Lambton 1st Earl Durham and Louisa Elizabeth Grey Countess Durham. He the son of Thomas Bruce 11th Earl Kincardine 7th Earl Elgin and Mary Nisbet Countess Elgin (age 68).

William Henry Frederick Cavendish and Emily Augusta Lambton were married. She the daughter of John "Radical Jack" Lambton 1st Earl Durham and Louisa Elizabeth Grey Countess Durham. They were third cousin once removed.