20 October 2020
– International Day of the Air Traffic Controller
1548 – Alonso de Mendoza founds the city of Nuestra Señora de La Paz (Our Lady of Peace) by appointment of the king of Spain and Holy Roman Emperor, Charles V.
1572 – Relief of Goes: Cristóbal de Mondragón, with 3000 soldiers of the Spanish Tercios, relieves the siege of the city.
1720 – The Royal Navy captures Caribbean pirate Calico Jack.
1740 – Maria Theresa takes the throne of Austria. France, Prussia, Bavaria, and Saxony refuse to honor the Pragmatic Sanction, and the War of the Austrian Succession begins.
1781 – The Patent of Toleration, providing limited freedom of worship, is approved in Habsburg Monarchy.
1803 – The United States Senate ratifies the Louisiana Purchase.
1805 – General Mack’s army surrenders to Napoleon at Ulm after a few skirmishes.
1818 – The Convention of 1818 is signed between the United States and the United Kingdom, which settles the Canada–United States border on the 49th parallel for most of its length.
1827 – In the Battle of Navarino, a combined Turkish and Egyptian fleet is defeated by British, French, and Russian naval forces in the last significant battle fought with wooden sailing ships.
1873 – Yale, Princeton, Columbia, and Rutgers universities draft the first code of American football rules.
1883 – Peru and Chile sign the Treaty of Ancón, by which the Tarapacá province is ceded to the latter, bringing an end to Peru’s involvement in the War of the Pacific.
1904 – Chile and Bolivia sign the Treaty of Peace and Friendship, delimiting the border between the two countries.
1910 – The hull of the RMS Olympic, sister-ship to the ill-fated RMS Titanic, is launched from the Harland and Wolff shipyard in Belfast, Northern Ireland.
1935 – The Long March, a mammoth retreat undertaken by the armed forces of the Chinese Communist Party a year prior, ends.
1939 – Pope Pius XII publishes his first major encyclical, entitled Summi Pontificatus.
1941 – World War II: Thousands of civilians in Kragujevac in German-occupied Serbia are murdered in the Kragujevac massacre.
1944 – The Soviet Army and Yugoslav Partisans liberate Belgrade, the capital of Yugoslavia.
1944 – Liquefied natural gas leaks from storage tanks in Cleveland and then explodes; the explosion and resulting fire level 30 blocks and kill 130.
1944 – American general Douglas MacArthur fulfills his promise to return to the Philippines when he commands an Allied assault on the islands, reclaiming them from the Japanese during the Second World War.
1946 – The Government of the Democratic Republic of Vietnam decides that Oct. 20 is Vietnam Women’s Day.
1947 – The House Un-American Activities Committee begins its investigation into Communist infiltration of Hollywood, resulting in a blacklist that prevents some from working in the industry for years.
1947 – The United States of America and the Islamic Republic of Pakistan establish diplomatic relations for the first time.
1951 – The “Johnny Bright incident” occurs in Stillwater, Oklahoma.
1952 – Governor Evelyn Baring declares a state of emergency in Kenya and begins arresting hundreds of suspected leaders of the Mau Mau Uprising, including Jomo Kenyatta, the future first President of Kenya.
1961 – The Soviet Union performs the first armed test of a submarine-launched ballistic missile, launching an R-13 from a Golf-class submarine.
1962 – The People’s Republic of China launches simultaneous offensives in Ladakh and across the McMahon Line, igniting the Sino-Indian War.
1968 – Former First Lady Jacqueline Kennedy marries Greek shipping tycoon Aristotle Onassis.
1970 – Siad Barre declares Somalia a socialist state.
1973 – “Saturday Night Massacre”: United States President Richard Nixon fires U.S. Attorney General Elliot Richardson and Deputy Attorney General William Ruckelshaus after they refuse to fire Watergate special prosecutor Archibald Cox, who is finally fired by Robert Bork.
1973 – Elizabeth II opens the Sydney Opera House after 14 years of construction work.
1976 – The ferry George Prince is struck by a ship while crossing the Mississippi River between Destrehan and Luling, Louisiana. Seventy-eight passengers and crew die, and only 18 people aboard the ferry survive.
1977 – Rock band Lynyrd Skynyrd’s plane crashes.
1981 – Two police officers and an armored car guard are killed during an armed robbery in Rockland County, New York, carried out by members of the Black Liberation Army and Weather Underground.
1982 – During the UEFA Cup match between FC Spartak Moscow and HFC Haarlem, 66 people are crushed to death in the Luzhniki disaster.
1991 – The Oakland Hills firestorm kills 25 and destroys 3,469 homes and apartments, causing more than $2 billion in damage.
1991 – A 6.8 Mw earthquake strikes the Uttarkashi region of India, killing more than 1,000 people.
2011 – Libyan Civil War: National Transitional Council rebel forces capture ousted Libyan dictator Muammar Gaddafi in his hometown of Sirte and kill him shortly after that.