The original meaning of military tattoo was a military drum performance, but subsequently it came to mean army displays more generally.
The term dates from around 1600 during the Thirty Years' War in the Low Countries (Belgium and the Netherlands). The Dutch fortresses were garrisoned with mercenary troops that were under federal command since 1594. The Dutch States Army had become a federal army, consisting mostly of Scottish, English, German and Swiss mercenaries, but commanded by a Dutch officer corps. Drummers from the garrison were sent out into the towns at 21:30 hrs (9:30PM) each evening to inform the soldiers that it was time to return to barracks. The process was known as doe den tap toe (Dutch for "turn off the tap"), an instruction to innkeepers to stop serving beer and send the soldiers home for the night. The drummers continued to play until the curfew at 22:00 hrs (10:00PM). Tattoo, earlier tap-too and taptoo, are alterations of the Dutch words tap toe which have the same meaning.
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