A Brief History of the Marque
Founded in 1901 as a motor vehicle firm, under the Argus name they produced an extensive range of engines for the aviation fledgling aviation industry beginning around 1906. They produced at least one engine for Sikorsky of Ukraine in 1910, and supplied engines to the German air force during the First World War.
In 1938 the Nazis forced the Jewish owner Moritz Straus to sell the firm, which was bought by Junkers for around half its real value. BMW had offered a quarter of its value. Straus fled to Switzerland and survived the Holocaust.
He had also owned a majority shareholding in Horch, which in the 1930s were the best-selling luxury cars in Germany. These automobiles were frequently seen with Hermann Goering and Adolph Hitler aboard, so it's rather ironic that they loved their Jewish cars. The Horch 930 was apparently Hitler's favourite.
At the time, Argus Motoren Gesellschaft had 3000 employees and a turnover of 25 million RM.
During the second war Argus supplied engines for the Fieseler Storch and the V1 "Buzzbomb", among others.
After 1945, they began motorcycle production, and being aviation experts they produced a machine which was propeller-driven. It was not a great success, and production ceased in 1948. (1)
In 1948 the Soviets dismantled the factory and moved it to Ettlingen.
1. No mention of a propeller-driven motorcycle exists in the source originally quoted, and there is no record of such a machine in any of the English or German language internet resources on the marque (May 2019). There is no entry for Argus in Tragatsch or Henshaw.
2. Although wikipedia.de claims a definite relationship to Beaufort in the UK, it is more likely that Beaufort was related to a different Argus of Germany which manufactured trucks.
Sources: Wikipedia.de, et al.