cavendish-bentinck was born in marylebone, london on 18 june 1897. he was the second son of frederick cavendish-bentinck, whose father, george cavendish-bentinck, was a grandson of william cavendish-bentinck, 3rd duke of portland. although formally victor cavendish-bentinck he was known informally as bill. like other members of his family he informally dispensed with the name "cavendish", being known simply as bill bentinck. he was educated at wellington college.