Anglo-Zanzibar War August 27, 1896

The Anglo-Zanzibar holds the distinction of being the shortest war in history, clocking in at 38 minutes.
When Khalid bin Barghash, the new Sultan of Zanzibar came to power in 1896, he wanted the country to be free from British control. One requirement by the British was for the new Sultan to seek permission for enthronement from a British consul. Barghash refused, which the British did not take lightly. They offered him a choice: leave the palace by his own free will or be removed forcefully.

When the appointed time came to make his decision, the Sultan responded by barricading himself within the palace and scrambling a defense force. Five British military vessels were in the harbor outside the palace and opened fire once the deal had expired.
Three Zanzibari ships were sunk, shore defenses were destroyed, and a handful of defending soldiers were killed. Although the fighting lasted less than an hour, over 500 Zanzibaris were killed or wounded, most from fires raging within the palace. British forces suffered one wounded and no deaths. After surrender, Sultan Barghash was deposed and granted political asylum in German East Africa while a new pro-British Sultan was installed.