In the 1930s and 1940s, three {{film serial}}s were made based on the ''ComicStrip/FlashGordon'' comic strip. They starred Buster Crabbe as Flash Gordon, Charles Middleton as Ming the Merciless, Jean Rogers as Dale Arden, and Frank Shannon as Dr Hans Zarkov.

The three serials were:

* ''Flash Gordon'' (1936)
* ''Flash Gordon's Trip to Mars'' (1938)
* ''Flash Gordon Conquers the Universe'' (1940)

The serials were syndicated on US television during the 1950s, under the title ''Space Soldiers'' to distinguish them from the 1954 ''[[Series/FlashGordon1954 Flash Gordon]]'' TV series starring Steve Holland.

These serials were among those that influenced the style of the ''StarWars'' movies, particularly their use of an OpeningScroll.

!!The 1930s film serials provide examples of:

* AdaptationDyeJob: Dale is brunette in the comic strip but was made blonde in the first serial -- even though this meant bleaching brunette Jean Rogers' hair -- because of the power of the HairOfGoldHeartOfGold trope.
* BaldOfEvil: Emperor Ming.
* BearsAreBadNews: Vultan's pet Urso.
* CatFight: Aura and just about every other female character at some point.
* ClothingDamage: Certainly close to an UrExample for SciFi. It happens in the very first installment to Flash, leading to him DressingAsTheEnemy.
* DefeatMeansFriendship: Thun the Lionman joins forces this way.
* DeflectorShields (in 1936!): The "Resistoforce" on Barin's ship.
* DetectiveMole: Ming tasks his High Priest of Tao with uncovering a traitor who provided Flash information. The Priest is the one who did so.
* DramaticUnmask: Ming's [[InTheHood masked]] champion swordsman is revealed to be Prince Barin.
* DressingAsTheEnemy: Flash.
* ElectricTorture: Used as a cliffhanger in the first serial.
* EvilerThanThou: Ming proves to be this for Azura; he backstabs her once he gains possession of her magic sapphire.
* {{Flynning}}
* GoGoEnslavement for Dale... and [[FanDisservice Zarkov]].
* HairOfGoldHeartOfGold: Dale, in the first serial.
* LovePotion: Ming tries one on Dale.
* NiceJobBreakingItHero: Flash single-handedly decimates a Lionman fleet... that was en route to assault Ming.
* NonIndicativeName: ''Flash Gordon Conquers the Universe''. The final installment features a tortured rationalization of the title that does not involve any actual universe-conquering.
* OpeningScroll: Invented it.
* PeopleInRubberSuits: Almost twenty years before Franchise/{{Godzilla}}.
* PublicDomainSoundtrack: Besides music cribbed from various previous Hollywood films, the score includes pieces by Music/JohannesBrahms, Music/FryderykChopin, Music/EdwardElgar, Music/FranzLiszt, Music/PyotrIlyichTchaikovsky, and Music/RichardWagner.
* SharkPool: A cliffhanger in the first serial involves Flash trapped in a tank with a giant octopus.
* {{Slurpasaur}}: The first of Mongo's denizens Flash faces.
* SpeakNowOrForeverHoldYourPeace: Flash and Thun [[WeddingSmashers crash]] Ming's [[AndNowYouMustMarryMe wedding to Dale]] before the gong is sounded the requisite 13 times. Which amounts to the same thing.
* StockFootage: Scenes of the destruction wreaked upon Earth by Ming and the resulting pancking crowds were stock footage from newsreels. ''Conquers the Universe'' used footage from the 1930 film ''The White Hell of Pitz Palu'' for establishing shots of the frozen wastes of Frigia. The second and third serials also made increasing use of recycled footage from earlier in the series.
* SyndicationTitle: In the 1950s the serials were syndicated on TV under the title ''Space Soldiers'' (there being an actual made-for-TV ''[[Series/FlashGordon1954 Flash Gordon]]'' series also airing at the time).
* TrapDoorFail: Inverted, as the door works fine on Flash, only Ming's daughter is inadvertently dropped, too.
* WeWillUseManualLaborInTheFuture