Curfew to cover fire
So this is interesting. Apparently when William The Conqueror crossed the puddle from Normandy with his army an overtook King Harold of England in the legendary 1066 Battle of Hastings, he marched over to London and declared himself king. This would change the big island forever, as King William ruled with an iron fist and squashed dissent pretty effectively. At first he was benevolent, they say. But then he decided to take a little vacation back to Normandy leaving his brother in charge.
On the morrow, there were a few rebellions so he came back and after that apparently he was ruthless. Among his many deeds, he ordered people to stay home after dark so nobody could cause trouble. He ordered all fires to be put out by 8pm as well. This was called “couvre feu” which is French for “to cover fire”. Eventually this morphed into curfew.
William, being from Normandy, installed all his cronies in high positions, and they all spoke French. One of his most notorious acts was to order a massive census so that he could appropriate the best lands for his vassals and also enable his goons to tax anybody who had any holdings, whether it be one pig or big estates. All this information is recorded in the “Doomesday Book”, which gives us a pretty accurate picture of the one million or so inhabitants of the United Kingdom at the time. Pretty nifty, huh?