Flash Gordon Conquers the Universe

Flash Gordon Conquers the Universe is a 1940 12-chapter science fiction Flash Gordon movie serial. It was the last of the three Flash Gordon serials by Universal Pictures.
Buster Crabbe plays Flash Gordon with Carol Hughes as Dale Arden, Frank Shannon as Dr. Zarkov, Shirley Deane as Princess Aura, and 
Charles B. Middleton as Ming the Merciless. Jean Rogers had played Dale Arden in the two previous Flash Gordon serials, but did not want to repeat the role. Hughes played the role.
Story.
Ming the Merciless causes a plague on Earth. Flash, Dale, and Zarkov distribute an antidote. Ming sends an army of robot bombs after the three. Flash and friends kill Ming by locking him in a tower, then crashing a rocket ship into it. Ming's last words are "I am the universe!". Zarkov announces that Flash Gordon has "conquered the universe".