Christians all over the world celebrate Christmas Day on 25 December.
But what else has happened on that day in history? Newsround has a few facts you might not know about this special day...
In 1066, fresh from beating the Saxons and invading the country, William the Conqueror was crowned King of England.
It wasn't such a good day for Mikhail Gorbachev in 1991, who quit as president of the Soviet Union, which used to control most of eastern Europe.
Mikhail Gorbachev quit his very important job on Christmas day
It got even worse for the Union the next day, as it dissolved on 26 December.
But that brought freedom to loads of countries, and ended the 50-year Cold War, so it's not all bad.
In a move for goodwill to all men in 1914, German soldiers stopped fighting with their British enemies in World War One.
The truce lasted long enough for them to sing carols, swap presents and even have a quick game of football.
History doesn't record what the score was, but we reckon it went to penalties.
Unsurprisingly, a couple of Christmas-type things have happened over the years.
In 1939, Charles Dickens' A Christmas Carol was read on radio for the first time, and Rudolph the Red-Nosed Reindeer appeared for the first time in shops in the US.
The world of pop got a boost on Christmas Day in 1971, when Florian Cloud de Bounevialle Armstrong, aka Dido, was born.
Beagle 2 went missing in 2003 - not a good Christmas present!
It's been a bit of a mixed bag for space exploration.
2003 saw Beagle 2, a European probe, crash on Mars. It has never been found.
But in 2004 the Cassini orbiter should launch its Huygens probe towards Saturn's moon, Titan, so there's hope yet!