A Roman Consul, on his way to fight a border war, stations a garrison of soldiers in a provincial town. The townspeople aren't happy with this situation but decide it's in their best interests to cooperate. However, the Tribune left in charge of the garrison proves to be cruel and demanding.
The action takes place in 1703 and Colbert wants to buy the duchy of Pignero ,unbeknowst to the old Duke. A sadistic villain (a count) is slowly poisoning the lord, besides he covets her daughter. The iron mask is here the duke's son, but the hangman's daughter takes pity on the unfortunate prisoner. The nasty traitor oppresses the poor, but André and his men (complete with priest) do their Robin Hood act.
An Italian submarine commander manages to sink an English warship and take its very British commander as prisoner. The film is based on the relationship which develops between the two characters.
