This document lists various notable events that occurred on Christmas Day throughout history, including:
Charlemagne being crowned Emperor of the Romans by the Pope in 800; William the Conqueror being crowned King of England in 1066; Isaac Newton, Pope Pius VI, and Clara Barton all being born on Christmas Day; Edmund Halley's prediction of Halley's Comet being confirmed in 1758; and General George Washington crossing the Delaware River on Christmas night in 1776.
More recent events mentioned are the internet's first test run on Christmas Day 1990; Mikhail Gorbachev resigning as Soviet President in 1991; and the USSR invading Afghanistan in 1979.