A Brief History of the Marque
Manufactured 1903 - 1925
Hans Grade of Brandenburg made cars, motorcycles and aeroplanes, all of which were powered by his own two-stroke engines. The motorcycles were designed by Hans Plog and used 118cc and 132cc engines.
Germany's first two aviators were bicycle racers, August Euler and Hans Grade. There is a Hans Grade museum in Borkheide Germany, and also an aviation club and a modelmaker's club of the same name. Grade won a small fortune in 1909 when he was awarded the prize for flying long and high, and is also credited with the design of the first airport. He founded Grade Flugzeugbau which produced some 80 aircraft prior to WWI.
He is famed in philately as the constructor of the aeroplanes which first flew airmail in Germany.
His list of accomplishments would certainly fill a book  - and a movie has been made in which Hans Grade starred as himself.
1. Karl-Dieter Seifert Hans Grade. Ein Leben in stürmischen Zeiten, Magdeburg 2008
Sources: wikipedia, philaseiten.de, et al