1265-First English Parliament summoned other than by royal command, in this instance by Simon de Montfort, Earl of Leicester. Meets in Westminster Hall.
1841-China cedes Hong Kong to the British during the First Opium War
1921-Republic of Turkey is declared from the remnants of the Ottoman Empire
1942-Nazi officials hold the notorious Wannsee Conference in Berlin to organize the "final solution", the extermination of Europe's Jews
1945-Franklin D. Roosevelt sworn-in for an unprecedented (and never to be repeated) 4th term as U.S. President
1981-Ronald Reagan inaugurated as the 40th President of the United States of America
2009-Barack Obama is inaugurated as the 44th President of the United States of America, becoming the United States' first African-American president
2025-Chinese start up DeepSeek launches AI model RI, with capabilities similar to other AI models but at a fraction of the cost, prompting experts to call it a “Sputnik moment