February 1 » Shinhan Bank, the oldest bank in South Korea, opens in Seoul.
April 30 » J. J. Thomson of the Cavendish Laboratory announces his discovery of the electron as a subatomic particle, over 1,800 times smaller than a proton (in the atomic nucleus), at a lecture at the Royal Institution in London.
June 16 » A treaty annexing the Republic of Hawaii to the United States is signed; the Republic would not be dissolved until a year later.
September 1 » The Tremont Street Subway in Boston opens, becoming the first underground rapid transit system in North America.
December 9 » Activist Marguerite Durand founds the feminist daily newspaper La Fronde in Paris.
December 30 » The British Colony of Natal annexes Zululand.
Day of death December 4, 1980
The temperature on December 4, 1980 was between -1.0 °C and 4.1 °C and averaged 1.1 °C. There was 5.7 mm of rain during 6.0 hours. There was 1.5 hours of sunshine (19%). The partly or heavily clouded was. The average windspeed was 2 Bft (weak wind) and was prevailing from the northwest. Source: KNMI
In The Netherlands , there was from Monday, December 19, 1977 to Friday, September 11, 1981 the cabinet Van Agt I, with Mr. A.A.M. van Agt (CDA/KVP) as prime minister.
March 14 » LOT Flight 7 crashes during final approach near Warsaw, Poland, killing 87 people, including a 14-man American boxing team.
March 18 » A Vostok-2M rocket at Plesetsk Cosmodrome Site 43 explodes during a fueling operation, killing 48 people.
April 2 » United States President Jimmy Carter signs the Crude Oil Windfall Profits Tax Act.
July 23 » Phạm Tuân becomes the first Vietnamese citizen and the first Asian in space when he flies aboard the Soyuz 37 mission as an Intercosmos Research Cosmonaut.
September 5 » The Gotthard Road Tunnel opens in Switzerland as the world's longest highway tunnel at 10.14 miles (16.32km) stretching from Göschenen to Airolo.
October 10 » The Farabundo Martí National Liberation Front is founded in El Salvador.
When copying data from this family tree, please include a reference to the origin: Hans Weening, "Family tree Weening", database, Genealogy Online (https://www.genealogieonline.nl/stamboom-weening/I138672.php : accessed October 18, 2026), "Sybren Leyenaar (1897-1980)".
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