Jacques Tourneur - Credited as Director in the English credits and as "A film by" in the Italian and French credits.
Bruno Vailati - Credited as Director in the Italian credits and as Producer in the English credits. According to Mylene Demongeot's autobiography, Tourneur did not have much involvement in directing the film, leaving most of the work to assistant director Vailati.
Mario Bava - credited as Director of photography and for Visual effects, Bava reportedly completed the film after Tourneur declined to extend his contract.
In 490 BC, as the immense Persian army of Darius I marches towards Greece, hoping to subjugate it by exploiting its internal divisions, a Greek soldier, Philippides, leads a fight against them. (from Google)