On December 12, 1939, Finnish forces defeated those of the Soviet Union in the first major victory of what became known as the Winter War, in the Battle of Tolvajärvi.
December 12th birthdays include:
* Erasmus Darwin (1731) – English physician, slave trade abolitionist, inventor and poet
* John Jay (1745) — First Chief Justice of the United States
* William Lloyd Garrison (1805) — American abolitionist, editor of The Liberator