Dr. Felix Heinrich Wankel (August 13, 1902–October 9, 1988) was the German inventor of the Wankel engine. Wankel was born in Lahr, Germany, in the upper Rhine Valley. Since his mother was widowed in World War I, Wankel received no university education or even an apprenticeship. However he was able to teach himself technical subjects and conceived the idea of the Wankel engine in 1924. In the 1930s, he had a disagreement with Adolf Hitler, and was imprisoned by the Nazis for some months. During World War II, he developed seals and rotary valves for German air force aircraft and navy torpedoes. After the war, he was imprisoned by the Allies for some months, his laboratory was closed, his work confiscated, and he was prohibited from doing more work. In 1951, he began development of the engine at NSU, leading to the first running prototype in 1957. His Wankel engine design was licensed and further developed and improved in 1959 and 1960 by Curtiss Wright in New Jersey before Mazda used these improvements in Japan. The engine has been successfully used by Mazda in several generations of their RX-series of coupés. In later years, Wankel was granted an honorary Doctorate of Engineering (Dr.-Ing.). He was known for his championing of animal rights and opposition to the use of animals in testing. Felix Wankel died in Heidelberg, having never been issued a driver's license.