Castlereagh-Canning duel

The Castlereagh-Canning duel was a pistol duel between the British Minister of War Viscount Castlereagh and Foreign Secretary George Canning, which took place on September 21, 1809, at Putney Heath. The reasons for the duel were the rivalry between the two politicians and numerous disagreements between them over the conduct of the war against Napoleonic France in 1808 and 1809. These differing opinions ultimately led to Canning's demand for a new appointment to the War Office in the spring of 1809, accompanied by a threat of his own resignation. Prime Minister Portland was reluctant to lose either Canning or Castlereagh and delayed a decision for an extended period. Instead, the matter was discussed with King George III and other members of the cabinet without Castlereagh's knowledge. Castlereagh was not immediately informed of the circumstances. He only became aware of the discussions in the late summer of 1809 and, in response, challenged Canning to a duel a few days later.

The duel, in which Canning was wounded in the leg by Castlereagh, resulted in the final collapse of the Portland government and the ascension of Spencer Perceval as the new prime minister. Castlereagh and Canning, meanwhile, spent several years on the backbenches, absent from any government responsibility.