William Ballantine was the son of a Thames Court police magistrate, William Ballantine.
He was called to the bar in 1834 and at the age of 44 became a Serjeant-at-Law. He was a well-known Counsel in some of the most famous cases of the day including the first Tichborne trial and the case of the 'murder of Mr Briggs in a carriage of the North London Railway on July 9, 1864'.
He was a witty, erudite and charming man, a popular member of gentlemen's clubs, and writer of two popular autobiographies.
Obituary, 'Death of Serjeant Ballantine', Times, London, 10 January 1887, p. 6.