The shortest recorded war lasted about 38 minutes

A war can end before a lunch break. The Anglo-Zanzibar War began on August 27, 1896, after Khalid bin Barghash claimed Zanzibar's throne and took the palace without British approval. Britain gave Khalid until 9:00 a.m. to leave and surrender his arms. 1

Khalid refused. British ships opened fire at about 9:02 a.m., and the palace caught fire. The royal yacht Glasgow also fired back before it was sunk. 1

The fighting ended after about 38 minutes in the commonly quoted account. Britannica gives the broader wording "no more than 40 minutes," because historical records differ on whether the opening order or the first shots begin the clock. 23

About 500 Zanzibari people were killed or wounded, while one British sailor was injured. The short clock measured the battle's duration; the casualty figures measure its human cost. 1