This film, despite being directed by Renoir, is largely forgotten today. This is a pity, as there are few films actually about the French Revolution (though it is used as a backdrop for a variety of plot lines), and none that really deal with the birth of the Republic.
It was made at the tail end of the 'Popular Front' government, a coalition of parties (including the communists) formed to protect the Third Republic from right-wing domestic subversion and the baleful influence of the Nazis.
It chose to use the early years of the revolution as a metaphor for this political situation - France was still a (constitutional) monarchy, and the King possessed the power of a constitutional veto. The Queen and her circle were said to be plotting a counter revolution.
Within this context, each city and region of France is requested to send a Battalion to Paris, to defend the government against its domestic enemies. We follow the adventures of some of the ordinary men in the battalion from Marseilles (who sing a new song called the "Marseilles" as they march. We see their experiences in Paris (including a love interest), and their simple and honest defence of what they believe in. Finally, they participate in the coup that leads to the establishment of the Republic and the arrest of the King.
The film is episodic, and some of the scenes are a little melodramatic. But the characterisation is excellent. The King and his court are not one-dimensional villains. The scene of his departure is quite moving.
In short, a film well worth rescuing from obscurity.