45

The shortest war in history was on this date, August 27, in 1896.  The British Empire defeated Zanzibar in 45 minutes

The Anglo-Zanzibar War was fought between the United Kingdom and Zanzibar on 27 August 1896. With a duration of only 45 minutes, it holds the record of being the shortest war in recorded history. The war broke out after Sultan Hamad bin Thuwaini, who had willingly co-operated with the British colonial administration, died on 25 August 1896, and his nephew, Khalid bin Bargash, seized power in what amounted to a coup d’état. The British favoured another candidate, Hamud bin Muhammed, whom they believed would be easier to work with, and delivered an ultimatum ordering Bargash to abdicate. Bargash refused. While Bargash’s troops set to fortifying the palace, the Royal Navy assembled five warships in the harbour in front of the palace. The British also landed parties of Royal Marines to support the “loyalist” regular army of Zanzibar. Despite the Sultan’s last-minute efforts to negotiate for peace via the U.S. representative on the island, the Royal Navy ships opened fire on the palace at 9 am on 27 August 1896 as soon as the ultimatum ran out. With the palace falling down around him and escalating casualties, Bargash beat a hasty retreat to the German consulate where he was granted asylum. The shelling stopped after 45 minutes. The British demanded that the Germans surrender the erstwhile Sultan to them, but he escaped to sea on 2 October 1896. He lived in exile in Dar es Salaam until captured by the British in 1916. He was later allowed to live in Mombasa where he died in 1927. As a final act, Britain demanded payment from the Zanzibar government to pay for the shells fired on the country.

For information of other short wars:  10 shortest wars