The shortest war in history occurred on August 27, 1896 between the United Kingdom and Zanzibar. The Anglo-Zanzibar conflict lasted only 38 minutes and was caused by a difference of opinion in who should succeed Sultan Hamad bin Thuwaini who had died on August 25th of that same year.
Sultan Khalid bin Barghash was not Britain’s preferred successor and was not in accordance with a 1886 treaty signed in 1886 that required the candidate obtain permission of the British consul. The British preferred Sultan Hamud bin Muhammed and demanded Khalid to stand down who instead called up his palace guard and barricaded himself inside the palace. 2800 civilians also defended the palace.
At 9:02 am, the British began their bombardment and disabled the Sultan’s defenses by 9:40 am. About 500 Zanzibaris were killed while only one British sailor was injured. Sultan Hamud was placed in power at the head of a puppet government. The war marked the end of Zanzibar as a sovereign state and the start of a period of heavy British influence. (Wikipedia)