This is a list of selected December 25 anniversaries that appear in the "On this day" section of the Main Page. To suggest a new item, in most cases, you can be bold and edit this page. Please read the selected anniversaries guidelines before making your edit. However, if your addition might be controversial or on a day that is or will soon be on the Main Page, please post your suggestion on the talk page instead.
Please note that the events listed on the Main Page are chosen based more on relative article quality and to maintain a mix of topics, not based solely on how important or significant their subjects are. Only four to five events are posted at a time and thus not everything that is "most important and significant" can be listed. In addition, an event is generally not posted this year if it is also the subject of the scheduled featured article or picture of the day.
To report an error when this appears on the Main Page, see Main Page errors. Please remember that this list defers to the supporting articles, so it is best to achieve consensus and make any necessary changes there first.
December 25: Christmas in Western Christianity and some Eastern Orthodox Churches
- 800 – In Rome's St. Peter's Basilica, Frankish King Charlemagne (bust pictured) was crowned Imperator Augustus by Pope Leo III as a rival of the Byzantine Emperor in Constantinople.
- 1100 – Baldwin of Boulogne was crowned as the first King of Jerusalem in the Church of the Nativity in Bethlehem.
- 1776 – American Revolutionary War: George Washington and his army crossed the Delaware River to launch a surprise attack on Hessian mercenaries at the Battle of Trenton.
- 1941 – World War II: The Japanese occupation of Hong Kong began after Mark Aitchison Young, the Governor of Hong Kong, surrendered the territory to Japan after 18 days of fierce fighting.
- 1947 – The Constitution of the Republic of China went into effect, amid the ongoing Chinese Civil War between the Kuomintang and the Communists.
- 2003 – The Beagle 2 space probe, part of the European Space Agency's Mars Express mission, disappeared shortly before its scheduled landing on Mars.