This Week: The Julian Calendar

Notable events in ancient history for the week of December 31 - January 6

January 1, 45 B.C. - The Julian Calendar goes into effect on this date. Introduced by Julius Caesar after consulting with Roman astronomers, the new calendar had a year of 365 days, 12 months, and a leap day added to February every four years. The Julian Calendar remained in use until 1583, when the Gregorian Calendar was adopted.

January 1, A.D. 404 - On this date, the last gladiatorial competition is held in Rome.

January 3, 106 B.C. - Roman orator and philosopher Cicero is born on this date.

January 4, 46 B.C. - Prominent Roman lieutenant Titus Labienus defeats Julius Caesar and his troops at the bloody Battle of Ruspina on this date. He dies in battle the next year fighting alongside Pompey.