His elder brother Henry Cavendish, 3rd Baron Waterpark succeeded their father in the family titles.
His sister Sarah Georgiana Cavendish married Sir George Philips, 2nd Baronet.
[1] On 27 March 1848, he joined the Canterbury Association and immediately became a member of the management committee.
It was an organisation set up to establish a colony to be known as Canterbury in the South Island of New Zealand.
Together with Lord Lyttelton, John Simeon and Edward Gibbon Wakefield, he guaranteed £15,000 to the Canterbury Association, which saved it from financial collapse.