John Gustavus Crosbie (circa 1749 – 6 July 1797) was an Anglo-Irish politician, mainly remembered for killing another Member of Parliament, Sir Barry Denny, in a duel in 1794.
[3] In October 1794 he caused a notable scandal by killing the sitting MP for the Kerry constituency, Sir Barry Denny, 2nd Baronet, in a duel.
As was the accepted practice at the time among members of the aristocracy, killing was treated as an affair of honour, although in law it was premeditated murder, and no action was taken against him.
[4] His sudden death three years later, after falling from his horse, was considered to be suspicious, and there is a local tradition that the Denny family poisoned him, in revenge for his killing of Sir Barry.
[5] Whether the rumour was true or false, the killing undoubtedly led to a bitter feud between the two families, which lasted for generations.