March 30 » German Society of Chemistry issues an invitation to other national scientific organizations to appoint delegates to the International Committee on Atomic Weights.
March 31 » Malolos, capital of the First Philippine Republic, is captured by American forces.
May 8 » The Irish Literary Theatre in Dublin produced its first play.
July 29 » The First Hague Convention is signed.
September 13 » Mackinder, Ollier and Brocherel make the first ascent of Batian (5,199 m - 17,058ft), the highest peak of Mount Kenya.
December 11 » Second Boer War: In the Battle of Magersfontein the Boers commanded by general Piet Cronjé inflict a defeat on the forces of the British Empire commanded by Lord Methuen trying to relieve the Siege of Kimberley.
Day of marriage August 27, 1920
The temperature on August 27, 1920 was between 7.7 °C and 18.8 °C and averaged 13.4 °C. There was 6.9 hours of sunshine (49%). The average windspeed was 3 Bft (moderate breeze) and was prevailing from the north. Source: KNMI
In The Netherlands , there was from September 9, 1918 to September 18, 1922 the cabinet Ruys de Beerenbrouck I, with Jonkheer mr. Ch.J.M. Ruys de Beerenbrouck (RKSP) as prime minister.
January 10 » League of Nations Covenant enters into force. On January 16 the organization holds its first council meeting, in Paris.
February 24 » Nancy Astor becomes the first woman to speak in the House of Commons of the United Kingdom following her election as a Member of Parliament (MP) three months earlier.
April 23 » The Grand National Assembly of Turkey (TBMM) is founded in Ankara. The assembly denounces the government of Sultan Mehmed VI and announces the preparation of a temporary constitution.
April 25 » At the San Remo conference, the principal Allied Powers of World War I adopt a resolution to determine the allocation of Class "A" League of Nations mandates for administration of the former Ottoman-ruled lands of the Middle East.
May 5 » Authorities arrest Nicola Sacco and Bartolomeo Vanzetti for alleged robbery and murder.
June 15 » Following the 1920 Schleswig plebiscites, Northern Schleswig is transferred from Germany to Denmark.
Day of death August 7, 1978
The temperature on August 7, 1978 was between 11.3 °C and 18.2 °C and averaged 14.7 °C. There was 0.6 mm of rain during 0.5 hours. There was 3.7 hours of sunshine (24%). The partly or heavily clouded was. The average windspeed was 2 Bft (weak wind) and was prevailing from the west. 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 15 » Somalia and Ethiopia signed a truce to end the Ethio-Somali War.
May 3 » The first unsolicited bulk commercial email (which would later become known as "spam") is sent by a Digital Equipment Corporation marketing representative to every ARPANET address on the west coast of the United States.
May 8 » The first ascent of Mount Everest without supplemental oxygen, by Reinhold Messner and Peter Habeler.
May 25 » The first of a series of bombings orchestrated by the Unabomber detonates at Northwestern University resulting in minor injuries.
July 11 » Los Alfaques disaster: A truck carrying liquid gas crashes and explodes at a coastal campsite in Tarragona, Spain killing 216 tourists.
September 15 » Muhammad Ali outpointed Leon Spinks in a rematch to become the first boxer to win the world heavyweight title three times at the Superdome in New Orleans.
When copying data from this family tree, please include a reference to the origin: Joop Klavers, "Family tree Klavers", database, Genealogy Online (https://www.genealogieonline.nl/stamboom_klavers/I18754.php : accessed February 20, 2026), "Hendrikus Cornelis Adrianus van Opstal (1899-1978)".
Copy warning
Genealogical publications are copyright protected. Although data is often retrieved from public archives, the searching, interpreting, collecting, selecting and sorting of the data results in a unique product. Copyright protected work may not simply be copied or republished.
Please stick to the following rules
Request permission to copy data or at least inform the author, chances are that the author gives permission, often the contact also leads to more exchange of data.
Do not use this data until you have checked it, preferably at the source (the archives).
State from whom you have copied the data and ideally also his/her original source.