While not the first film to use dissolves to represent flashbacks, it was considered too new a method in the language of cinema that its producers' insisted on pre-title cards to avoid any confusion.
Jean Gabin's monologue to the crowd towards the end of the movie is famous. He delivered it so intensely that immediately afterwards he cried his eyes out in his dressing room.
The main square, on which the movie opens and in which some scenes occur afterwards, was created for the movie, including the buildings, shops, street and the tall building in which the main character lives. The back side was open, which facilitated shooting inside and allowed the acclaimed travelling shot from top to bottom of the staircase.
RKO remade this film as La longue nuit (1947) and tried to have all this film's original prints destroyed.
This film was released in June 1939, only a year before France's surrender to the Nazis, who subsequently occupied the country. Although this film has no overt political content, according to film scholar Roy Armes, the scene in which the crowd on the street below expresses solidarity with the trapped François--which he rejects, shouting that he only wants to be left alone--reflected the political despair of the period, "a chilling epilogue to a brief period which had opened with the enthusiasms aroused by the Popular Front." [French Cinema, Oxford University Press, 1985, p. 102] In validation of this view, the collaborationist government of Vichy (unoccupied France) shortly afterwards banned the film as "demoralizing," as if it had been partly responsible for France's defeat.