This Day in History: 0000-01-03

3 Jan – Pope Leo X excommunicated Martin Luther, the Protestant Reformer, in his papal bull Decet Romanum Pontificem, after Luther refused to recant his writings as required by the 1520 papal bull Exsurge Domine (1521).
3 Jan – In the Battle of Princeton, American forces under Washington defeated British troops under Cornwallis, compelling the British to abandon most of New Jersey (1777).