Career
A stage actor and silent film pioneer, Shannon made his screen debut in 1913"s The Artist"s Joke. He later appeared in dozens of films through the mid-1920s, including and Monsieur Beaucaire (1924). Shannon then returned to the stage until beckoned back to Hollywood in 1931 and played a few substantial supporting parts, including Captain McTavish in Warner Brothers" Torchy Blaine series from 1937 to 1939, but he is most fondly remembered as the brilliant scientist Doctor Alexis Zarkov in the three Flash Gordon serials starring Buster Crabbe between 1936 and 1940.
He worked afterwards as a writer for the television-series Tales of the Texas Rangers between 1955 and 1958.
Shannon died in Hollywood, Los Angeles, California at the age of 84. He is interred at Holy Cross Cemetery, Culver City, California.