The shortest war in recorded history started at 9:02 in the morning and finished at 9:40, and the side that lost it was afterward required to pay 300,000 rupees — the cost of the shells the Royal Navy had fired into its palace, damages included

Khalid bin Barghash had 2,800 men and an arsenal assembled almost entirely from imperial gifts. What he did not have was a navy.

At nine on the morning of 27 August 1896, five British warships lay off the harbor at Zanzibar with their guns trained on his palace, and the deadline he had been given to walk out of it had just run out. Thirty-eight minutes later it was over. No war on record has been shorter.

That last sentence is very nearly all that survives in popular memory, and it has been doing a lot of quiet work.

Why Britain got a say in who ruled Zanzibar

Sultan Hamad bin Thuwaini died on 25 August. Within hours his nephew Khalid had moved into the palace.

On its own that was ordinary enough. The obstacle was a document signed six years earlier: the Heligoland-Zanzibar Treaty of 1890, under which Britain and Germany divided their spheres in East Africa and Zanzibar became a British protectorate. Its terms meant no sultan took the throne without British consent. Britain wanted Hamoud bin Mohammed, reckoned in the diplomatic correspondence of the period to be friendlier to British interests. Khalid was not that man, and he had not asked.

Rear-Admiral Harry Rawson gave him until nine o'clock on the 27th to haul down his flag and leave.

Where the guns came from

Roughly 2,800 people were inside the compound when the deadline expired. Most were civilians pulled in over the previous two days; about 700 were trained Askari soldiers who had come over to Khalid, alongside the palace guard and the sultan's own household.

The artillery says more about his position than any of it. He had several Maxim guns; a Gatling gun presented by Queen Victoria; two 12-pounder field guns given by Kaiser Wilhelm II; and a bronze cannon cast sometime in the seventeenth century. Nearly every serious weapon pointing at the Royal Navy that morning had arrived as a diplomatic gift from one of the two empires that had already settled between themselves who was permitted to rule the island.

The buildings were worse than the guns. The compound was three structures joined by covered wooden bridges above street level: the palace, an attached harem called the Beit al-Hukm, and the Beit al-Ajaib (the House of Wonders, the first building in East Africa to be wired for electricity). They were built largely of local timber. None of it was meant to stop naval gunfire.

Thirty-eight minutes

At 9:00, General Lloyd Mathews gave the order. At 9:02, HMS Racoon, Thrush and Sparrow opened fire together.

Thrush's first shell dismounted one of the Kaiser's 12-pounders where it stood.

Three minutes in, the sultan's yacht joined. HHS Glasgow was a wooden sloop built in 1878, carrying seven nine-pounders and another Gatling gun that had also come from Queen Victoria, and she fired on the British flagship St George. The return fire sank her. The harbor was shallow enough that her masts stayed above the waterline; her crew ran up a British flag and were taken off by British launches.

Ashore, the timber caught. The defenders had built barricades out of crates, bales and rubber, and the rubber burned. The fire started moving toward the customs sheds, where explosives were stored, so British sailors landed and organized a fire brigade to stop it reaching them.

The flag came down at about 9:40.

Then the figures the trivia leaves out. Around 500 of Khalid's people were killed or wounded. Perhaps twenty more died in the looting afterward. On the British side, one petty officer was hurt.

How Khalid got out

He never surrendered.

He left the palace with about forty followers and reached the German consulate, where the consul, Albrecht von Rechenberg, refused to give him up; the German extradition treaty carried an exception for political prisoners, and Rechenberg invoked it. Khalid stayed five weeks. On 2 October the German warship SMS Seeadler came in, and at high tide he stepped from the consular grounds directly onto her deck without setting foot on ground where the British could arrest him. He was landed at Dar es Salaam in German East Africa.

They caught up with him twenty years later, during the East African campaign of the First World War. He was exiled to the Seychelles and then to Saint Helena, eventually allowed back to the mainland, and died at Mombasa in 1927.

What happened afterward

Hamoud bin Mohammed was installed the same day. He was a figurehead and everyone involved understood it; the sultanate survived because administering Zanzibar directly as a crown colony would have cost more than administering it through him.

Then the accounting. Khalid's supporters were required to pay 300,000 rupees, covering the shells fired at them plus the damage done in the looting those shells had set off. The ships had fired around 500 shells in those thirty-eight minutes, along with 4,100 machine gun rounds and 1,000 rounds from rifles.

Within months, at British prompting, Hamoud abolished slavery in all its forms. That sentence is usually where the story is allowed to stop, and it flatters everyone. The decree required an enslaved person to present themselves at a government office in order to be freed. Over its first ten years it produced 17,293 emancipations, against an enslaved population estimated at 60,000 in 1891.

The House of Wonders came through the shelling more or less intact and became the administrative center of the British-run government. During repairs the following year a clocktower went up on its front, replacing the lighthouse the shells had knocked down.

Worth saying where this comes from. The account is reconstructed almost entirely from British naval and administrative records. The 500 casualties are an estimate rather than a list of names, and very little survives from the other side of it.

Why this is the colonial war everyone knows

The protectorate that the bombardment settled ran another sixty-seven years.

Britain fought a great many actions like this one in the 1890s. The Benin punitive expedition came the following year, and almost nobody outside the specialist literature can tell you anything about it. This one has a number attached to it, and thirty-eight minutes is both exact enough to repeat and short enough to be funny, so it travels without any help.

The number is also doing something while it travels. Thirty-eight minutes sounds like a war in which very little happened: a farce, or a diplomatic incident with cannons. It took thirty-eight minutes because one side had five modern warships and the other had a timber palace and a collection of guns donated by the people shelling it. That is what a demonstration looks like, and it was meant to be one. The invoice is the proof. Nobody sends you a bill for a battle.