Lord Winchilsea wrote in a published letter that, ‘under the cloak of some outward show of zeal for the Protestant religion’, Wellington had in proceeding with Catholic Emancipation carried out ‘insidious designs for the infringement of our liberties, and the introduction of Popery into every department of the State.’ As a result, the two men met for a duel at Battersea Fields, the duke attended by Sir Henry Hardinge and Winchilsea by Edward Boscawen, Viscount Falmouty. Wellington fired wide and then Winchilsea fired in the air. The duke later insisted that he was defending not his personal honour but the right of public figures to change their opinions.

See DNB and The Times, 23 March 1829.