1920January 1920 January 1 Polish–Soviet War in 1920: The Russian Red Army increases its troops along the Polish border from 4 divisions to 20. Kauniainen, completely surrounded by the city of Espoo, secedes from Espoo as its own market town. January 3 – The 1920 Xalapa earthquake in Mexico kills over 600 people, making it the second deadliest in the country. January 7 – Russian Civil War: The forces of Russian White Admiral Alexander Kolchak surrender in Krasnoyarsk; the Great Siberian Ice March ensues.
1973January 1973 January 1 – The United Kingdom, the Republic of Ireland and Denmark enter the European Economic Community, which later becomes the European Union. January 15 – Vietnam War: Citing progress in peace negotiations, U.S. President Richard Nixon announces the suspension of offensive action in North Vietnam. January 17 – Ferdinand Marcos becomes President for Life of the Philippines. January 20 – Richard Nixon is sworn in for a second term as President of the United States.
1886January 1 – Upper Burma is formally annexed to British Burma, following its conquest in the Third Anglo-Burmese War of November 1885. January 5–9 – Robert Louis Stevenson's novella Strange Case of Dr Jekyll and Mr Hyde is published in New York and London. January 16 – A resolution is passed in the German Parliament to condemn the Prussian deportations, the politically motivated mass expulsion of ethnic Poles and Jews from Prussia, initiated by Otto von Bismarck.
1905As the second year of the massive Russo-Japanese War begins, more than 100,000 die in the largest world battles of that era, and the war chaos leads to the 1905 Russian Revolution against Nicholas II of Russia (Shostakovich's 11th Symphony is subtitled The Year 1905 to commemorate this) and the start of Revolution in the Kingdom of Poland. Canada and the U.S. expand west, with the Alberta and Saskatchewan provinces and the founding of Las Vegas.
1919January 1919 January 1 The Czechoslovak Legions occupy much of the self-proclaimed "free city" of Pressburg (now Bratislava), enforcing its incorporation into the new republic of Czechoslovakia. HMY Iolaire sinks off the coast of the Hebrides; 201 people, mostly servicemen returning home to Lewis and Harris, are killed. January 2–22 – Russian Civil War: The Red Army's Caspian-Caucasian Front begins the Northern Caucasus Operation against the White Army, but fails to make progress.
1972Within the context of Coordinated Universal Time (UTC) it was the longest year ever, as two leap seconds were added during this 366-day year, an event which has not since been repeated. (If its start and end are defined using mean solar time [the legal time scale], its duration was 31622401.141 seconds of Terrestrial Time (or Ephemeris Time), which is slightly shorter than 1908). January 1972 January 1 – Kurt Waldheim becomes Secretary-General of the United Nations.
1838January 10 – A fire destroys Lloyd's Coffee House and the Royal Exchange in London. January 11 – At Morristown, New Jersey, Samuel Morse, Alfred Vail and Leonard Gale give the first public demonstration of Morse's new invention, the telegraph. January 21 – The first known report about the lowest temperature on Earth is made, indicating in Yakutsk. January 23 - A 7.5 earthquake strikes the Romanian district of Vrancea causing damage in Moldavia and Wallachia, killing 73 people.