Wikipedia:Selected anniversaries/January 20

January 20:

• 1320 – After reuniting Poland, Władysław the Short (sarcophagus figure pictured) was crowned king in Kraków.

• 1885 – LaMarcus Adna Thompson, sometimes called the "Father of Gravity", patented the roller coaster.

• 1921 – The first Turkish Constitution was ratified by the Grand National Assembly, making fundamental changes in Turkey by enshrining the principle of national sovereignty.

• 1942 – World War II: At the Wannsee Conference held in the Berlin suburb of Wannsee, senior Nazi German officials decided the "Final Solution to the Jewish Question", accelerating The Holocaust.

• 1990 – Black January: The Soviet Red Army violently cracked down on Azeri pro-independence demonstrations in Baku, Azerbaijan SSR.