December 25th is not actually the day of Jesus’ birth – everyone was using a rather different calendar back then anyway. Rather, it’s as with Brenda, the official birthday. Held at a time each year that is convenient to those organising it. In this case, the Catholic Church. Who noted that the Northern Europeans feasted and gorged at this point in time each year so decided there ought to be some Church point to it all. Can’t allow the people to be having fun without there being an approved reason now, can we? The gorging being a feature of Northern European farming, this being about when the fresh meat runs out until the spring lamb arrives – which is one reason we’ve that association with Easter for the meat. That’s why it was 352 AD before we know it was celebrated today. And 597 before we adopted the Julian calendar so we did too.
Mikhail Gorbachov proves the ineffectiveness of government by resigning on this day.
The British demonstrate the effectiveness of colonialism by surrendering Hong Kong to the Japanese.
Charlemagne manages to keep government together for just the one generation by being crowned Emperor today.
William the Bastard starts off a rather better track record by being crowned King of England.
Yes, obviously enough, Silent Night (Stille Nacht) first sung on this day.
Less obviously, White Christmas first heard. This being back in the time when Christmas didn’t start in August – and yes, today is the start of the 12 days of Christmas, not the end.