1777 - Lydia Barrington Daragh gets word to George Washington of British plans to attack that night at Whitemarch, allowing the Continental Army time to arm and be ready (okay, I cheated. This event is not on wikipedia. But wikipedia is rather shy on women's history).
1952 - Great Smog of 1952: A cold fog descends upon London, combining with air pollution and killing up to 12,000 in the weeks and months that follow.
2005 - Tens of thousands of people in Hong Kong protested for democracy and called on the Government to allow universal and equal suffrage.
1860 - Lillian Russell (Helen Louise Leonard) - one of the most famous and beautiful actresses of the late 19th century and early 20th century.
1945 - Roberta Bondar - Canadian astronaut and scientist.
1696 - Empress Meisho of Japan (b. 1624)
Oh, and in roman times, secret ceremonies in honor of Bona Dea (Goddess of fertility, healing, virginity and women) were held on December 4.