The shortest war in history lasted only 38 minutes - Apparently.
The Anglo-Zanzibar War on August 27, 1896, between the United Kingdom and Zanzibar, is recorded by the Guinness World Records as the shortest war in history. The war began when Zanzibar's pro-British Sultan Hamad bin Thuwaini died, and the opposing faction installed a rival sultan, who was not recognized by the UK. The British launched a naval attack on Zanzibar, which surrendered after just 38 minutes, resulting in the death of 500 Zanzibari soldiers.