August Euler was a very important German aviation pioneer; he gained German pilot’s license No.1, designed and built airplanes, was a flight instructor, created a flight school, and founded an aircraft company bearing his name. After WWI he served as Germany’s first Secretary of State for aviation. This is the story of Euler and his aircraft for the first time in English. It is translated and expanded from Abenteuer Gelber Hund by Michael Düsing. The book is published in two volumes totaling 440 pages with 396 photos and 136 drawings and other graphics plus 1/48 scale drawings of six Euler aircraft. Volume 2 has 234 pages, 161 photos, 136 graphics, and scale drawings of 4 aircraft.