Flash Gordon started life as a hero of a science fiction comic strip originally drawn by Alex Raymond. First published January 7, 1934, it as inspired by and created to compete with the already established Buck Rogers strip.
Starting April 22, 1935, the strip was adapted into The Amazing Interplanetary Adventures of Flash Gordon, a 26-episode weekly radio serial. The series followed the strip very closely, amounting to a week-by-week adaptation of the Sunday strip for most of its run.
Flash Gordon was played by Gale Gordon, later famous for his television roles in Our Miss Brooks, Dennis the Menace, The Lucy Show and Here's Lucy (the latter two with Lucille Ball). The cast also included Maurice Franklin as Dr. Zarkov and Bruno Wick as Ming the Merciless.
The radio series broke with the strip continuity in the last two episodes, when Flash, Dale and Zarkov returned to Earth. They make a crash landing in Africa, where they meet Jungle Jim, the star of another of Alex Raymond's comic strips.
The series ended on October 26, 1935 with Flash and Dale's marriage. The next week, The Adventures of Jungle Jim picked up in that Saturday timeslot.
Two days later, on October 28, The Further Interplanetary Adventures of Flash Gordon debuted as a daily show, running five days a week. This series strayed further from Raymond's strip, involving Flash, Dale and Zarkov in an adventure in Atlantis. The series aired 74 episodes, ending on February 6, 1936. (Source: wikipedia.org)