Mercier was born into a wealthy family; her father was a French pharmacist and her mother Italian.

The circumstances of war made this difficult and her parents saw it as only a whim; however, her determination won through and she joined the "ballet-rats", as the dancers of the chorus are termed.

She moved to Paris aged 17, and first joined the troupe of Roland Petit, then the company of the "Ballets of the Eiffel Tower".

After some romantic comedies and a small role in François Truffaut's Tirez sur le pianiste ("Shoot The Pianist", 1960), she worked in England and made some films in Italy, mainly with a small budget and usually playing women of easy virtue.

Catherine Deneuve was too pale, Jane Fonda spoke French with an American accent, and Virna Lisi was busy in Hollywood.

It catapulted her to almost instant stardom, rivalling Brigitte Bardot in celebrity and popularity, but the character overshadowed all other aspects of her career.

[2] Attempting to break free from the character of Angélique, Mercier played against Jean Gabin in The Thunder of God, directed by Denys de la Patellière.

The actress confessed in Nice-Matin: "I am ruined, I'll be obliged to sell part of my paintings, my furniture, my properties, my jewels and the costumes of Angélique".