January 30 » The first Anglo-Japanese Alliance is signed in London.
April 2 » Dmitry Sipyagin, Minister of Interior of the Russian Empire, is assassinated in the Marie Palace, Saint Petersburg.
April 18 » The 7.5 Mw Guatemala earthquake shakes Guatemala with a maximum Mercalli intensity of VIII (Severe), killing between 800–2,000.
May 31 » Second Boer War: The Treaty of Vereeniging ends the war and ensures British control of South Africa.
August 22 » Theodore Roosevelt becomes the first President of the United States to make a public appearance in an automobile.
December 28 » The Syracuse Athletic Club defeated the New York Philadelphians, 5–0, in the first indoor professional football game, which was held at Madison Square Garden.
Day of marriage November 12, 1921
The temperature on November 12, 1921 was between -1.7 °C and 3.1 °C and averaged -0.2 °C. There was 3.1 hours of sunshine (34%). The average windspeed was 1 Bft (weak wind) and was prevailing from the east-southeast. 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 20 » The British K-class submarine HMS K5 sinks in the English Channel; all 56 on board die.
February 25 » Georgian capital Tbilisi falls to the invading Russian forces after heavy fighting and the Russians declare the Georgian Soviet Socialist Republic.
March 31 » The Royal Australian Air Force is formed.
June 12 » Mikhail Tukhachevsky orders the use of chemical weapons against the Tambov Rebellion, bringing an end to the peasant uprising.
July 10 » Belfast's Bloody Sunday: Sixteen people are killed and 161 houses destroyed during rioting and gun battles in Belfast, Northern Ireland.
October 26 » The Chicago Theatre opens.
Day of death June 30, 1949
The temperature on June 30, 1949 was between 8.8 °C and 20.5 °C and averaged 14.7 °C. There was 11.0 hours of sunshine (66%). The average windspeed was 3 Bft (moderate breeze) and was prevailing from the northwest. Source: KNMI
From August 7, 1948 till March 15, 1951 the Netherlands had a cabinet Drees - Van Schaik with the prime ministers Dr. W. Drees (PvdA) and Mr. J.R.H. van Schaik (KVP).
When copying data from this family tree, please include a reference to the origin: Jan Kaper, "Family tree Kaper", database, Genealogy Online (https://www.genealogieonline.nl/stamboom-kaper/I44429.php : accessed February 16, 2026), "Jan de Boer (1902-1949)".
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