December 25

1776:

American War of Independence: George Washington and his army crossed the Delaware River to launch a surprise attack on Hessian mercenaries at the Battle of Trenton.

1914:

World War I: The Christmas truce: Just after midnight on Christmas morning, German and British troops on the Western Front cease firing their guns and artillery and sing Christmas carols. Crossing the No man's land, they trade gifts with the enemy forces that face them. They also played a game of football with a makeshift ball (fashioned by the Germans) This truce lasts for several days, depending on the location.

1941:

Hong Kong surrenders

1943:

Canadians celebrate Christmas in Ortona