The shortest war in history lasted only 38 minutes - Apparently.
The Anglo-Zanzibar War, fought between the United Kingdom and Zanzibar on August 27, 1896, is recorded as the shortest war in history. The conflict began when the pro-British Sultan Hamad bin Thuwaini died, and the opposing faction, backed by Germany, installed a new sultan. The UK demanded Zanzibar recognize the new sultan, but the opposing faction refused, leading to the brief war. The British warship HMS Philomel bombarded Zanzibar, and the opposing forces surrendered after just 38 minutes.