This weekend marks the anniversary of the beginning of the Anglo-Swedish war.

Never heard of it? Well, mostly because it’s a war that didn’t really happen.

Oh, it’s real. On November 17, 1810, Sweden declared war on the United Kingdom.

Sweden and the U.K. were allies, but in 1810, when Sweden lost a war with France — the U.K. had it’s own little off and on war with France going on, but it was a separate war. As a result of Sweden’s defeat, France was actually running things. They demanded that Sweden declare war on the U.K. so they did. They just never got around to fighting.

Sweden allowed the U.K. to occupy an island that was used as a base for smuggling. That was okay with Sweden because the U.K. was such a huge trading partner that when France insisted all trade stop, it did. Well, all the legal trade. Sweden kept on doing business, but called it British smuggling and never managed to stop any of it, on purpose.

The war finally ended a couple of years later with some other treaty.

That’s how you do a war.