- 884 12 Dec Charles the Fat inherits West Frankish lands, briefly reuniting the empire of his ancestor Charlemagne.
- 1189 12 Dec Richard I leaves England, where he spent less than six months of his reign, to join the Third Crusade.
- 1901 12 Dec Gugliemo Marconi sends the first transatlantic wireless signals from Poldhu, Cornwall to Newfoundland.

