January 30 is the thirtieth day of the year in the Gregorian calendar. 335 days (336 in leap years) remain in the year after this day.
1018 - The German-Polish War ends with the signing of the Peace of Bautzen between the Holy Roman Emperor Heinrich II and the Polish Prince Boleslaw I.
1648 - The signing of the Peace of Minster marks the end of the Eighty Years' War between Spain and the United Provinces of the Netherlands.
1649 - King Charles I is executed in London for treason after defeating his forces in a civil war with Oliver Cromwell's Republican forces.
1661 - Oliver Cromwell, Lord Protector of the Commonwealth of England, is ritually executed two years after his death, on the anniversary of the king's overthrow.
1661 - A Polish-Lithuanian state union cedes Kiev, Smolensk, and part of Ukraine east of the Dnieper to the Russian Empire under an Andrusovo armistice.
1826 - The Menay Bridge opens between Wales and the Isle of Anglesey, considered the first modern suspension bridge.
1841 - A fire destroys two-thirds of the Puerto Rican city of Mayaguez.
1847 - The city of Jerba Buena in California is renamed San Francisco.
1862 - The first American armored vehicle, the USS Monitor, is launched.
1913 - The British House of Lords rejects the Irish Self-Government Act.
1933 - Adolf Hitler is sworn in as German chancellor.
1937 - Thirteen Communist Party officials are sentenced to death for allegedly participating in Leo Trotsky's plot against the top of the state.
1937 - Adolf Hitler declares in the Reichstag that Germany is withdrawing its signature from the Versailles Peace Treaty.
1943 - The Royal Air Force begins the first day and night bombing of Berlin.
1945 - Wilhelm Gustoff, overcrowded with German refugees, sinks in the Baltic Sea after being torpedoed by a Soviet submarine, killing about 9,500 people, the largest maritime accident.
1964 - For the first time in the history of cosmonautics in the USSR, satellites launched into different orbits with the help of one rocket, "Electron 1" and "Electron 2"
1967 - Pope Paul VI meets with President of the Presidium of the Supreme Soviet of the USSR Nikolai Podgorny, the first head of the Soviet state to visit the Vatican.
1968 - A month-long Tet offensive begins in the Vietnam War, under the command of North Vietnamese General Vo Ngu�