AD 336, 1st recorded celebration of Christmas on Dec. 25 occurs in Rome.
AD 376, In Milan, Ambrose, the Bishop of Milan, forces the emperor Theodosius to perform public penance for his massacres
AD 597, England adopts Julian calendar
AD 795, Adrian I ends his reign as Catholic Pope
AD 800, The pope crowns Charlemagne emperor in Rome
AD 1066, William the Conqueror crowned king of England
AD 1223, St. Francis of Assisi assembles 1st nativity scene (Greccio, Italy)
AD 1651, Massachusetts orders 5 shilling fine for observing Christmas
AD 1818, "Silent Night" by Franz Gruber & Joseph Mohr sung for 1st time
AD 1818, 1st US performance of Handel's "Messiah," Boston
AD 1831, La. & Ark. becomes 1st states to observe Christmas as a legal holiday
AD 1914, German and British troops on the Western Front declare an unofficial truce to celebrate Christmas during World War I