The shortest war in history lasted only 38 minutes - Apparently.
The Anglo-Zanzibar War between the United Kingdom and Zanzibar on August 27, 1896, is recorded by the Guinness World Records as the shortest war in history. The war began when the pro-British Sultan Hamad bin Thuwaini died, and the opposing faction proclaimed a new sultan, leading the British to demand recognition of their preferred candidate. Zanzibar refused, and the British launched a naval attack, which lasted only 38 minutes before Zanzibar surrendered.