Frank Whittle designed the first true jet engine between 1928 and 1930, but it was not used to fly a jet aircraft until 1941. Meanwhile, the German engineer Hans von Ohain began work on a similar jet engine in 1936. His engine had flown a Heinkel aircraft by 1939. German developments proceeded more rapidly, and Germany had a jet fighter plane in action before the end of World War it.
Picture credit: google