Wikipedia:Selected anniversaries/January 20
- 1265 - Summoned by Simon de Montfort, the first English parliament held its first meeting in the Palace of Westminster.
- 1320 - After reuniting Poland, Wladislaus the Short was crowned king in Kraków.
- 1885 - LaMarcus Adna Thompson patented the roller coaster.
- 1892 - The first official basketball game was played at the YMCA in Springfield, Massachusetts.
- 1942 - Nazis at the Wannsee conference in Berlin decided the "final solution to the Jewish question", leading eventually to the Holocaust.
Recent days: January 19 – January 18 – January 17