Charles William Frederick Cavendish-Bentinck, was the second child and eldest son of Lord William Charles Augustus Cavendish-Bentinck, and his second wife, Anne Wellesley, and was born 8 November 1817.
He married first, 26 September 1839, Sinetta Lambourne, daughter of James Lambourne. She died 19 February 1850,  having had 4 children who all died as infants.
His second marriage was with Caroline Louisa Burnaby on 13 December 1859. She was the eldest daughter of Edwyn Burnaby, of Baggrave Hall, Leicestershire.
They had three daughters;
Nina Cecilia Cavendish-Bentinck, born 11 September 1862;
Anne Violet Cavendish-Bentinck, born 1864, twin with the following;
Hyacinth Cavendish-Bentinck, born 1864, twin with the preceding.
He died at Ridgmount on 17 August 1865 and his will was proved on 12 September 1865 at the Principal Registry office. His widow was the sole Executrix and her residence was described as 50 Eaton Place, Pimlico. His effects were valued at under £4,000.
His widow, married secondly on 30 November 1870, Harry Warren Scott, 3rd son of Sir William Scott, of Ancrum.
↑ Principal Probate Registry. Calendar of the Grants of Probate and Letters of Administration made in the Probate Registries of the High Court of Justice in England: Wills 1865; London; digital images, Ancestry.com. database England & Wales, National Probate Calendar (Index of Wills and Administrations), 1858-1966, 1973-1995, entry for Bentinck, the Reverend William Charles Cavendish. p. 194