It is a Belle Époque tragedy, the story of an ill-fated love affair between characters played by Simone Signoret and Serge Reggiani.

The story was loosely based on an infamous real-life love triangle between the prostitute Amélie Élie and the Apache gang leaders Manda and Leca, which was the subject of much sensational newspaper reporting during 1902.

In Belle Époque Paris, Marie, a beautiful woman of the demimonde known for her golden hair, is unhappily involved with Roland, a brutish criminal who is a part of a local syndicate headed by Félix Leca.

Anatole, a waiter at L'Ange Gabriel, noticed the trouble brewing and alerted the police, who arrive at the scene while the gang members are attempting to get rid of Roland's body.

While the frustrated inspector is telling him that he is being charged as an accessory to Roland's murder, Raymond glimpses Leca's name in a note, revealing his boss' duplicity.

As British film critic Roy Armes wrote, "Becker shows all the hurried ugliness and squalor that surrounds the guillotine, so that we feel this execution to be an affront to humanity.

He wrote: "If you're at all interested in how stories are constructed, you cannot fail to admire the ingenuity of the plot, particularly the strong, oblique, unexpected way it gets abruptly to Manda's execution in a scene that is as beautiful as it is mysterious, as the Casque d'Or [Marie] arrives in the middle of the night at a disreputable hotel.

The drawing of the shady milieu, the deeply human interpretation of the love relationship between Manda and Marie – that is fascinatingly dramatised and convinced not least by the excellent actors Simone Signoret and Serge Reggiani.

Despite the bleak plot, the film has a life-affirming trait, especially in the exterior shots, which is primarily due to the strong charisma of Simone Signoret in the leading role.

[9] In Don Winslow's 2011 novel Satori, the main female character, Solange Picard, watches Casque d'Or repeatedly in a cinema in Saigon, crying at the end each time.