History is littered with tales of those whose own self-belief and confidence belied their actual ability. It’s an arguably admiral and endearing character trait which has traditionally been associated with eccentricity, but more recently with mental health issues. Florence Foster Jenkins was a socialite and operatic soprano who was ridiculed for her atrocious singing ability. Marguerite is a new film from Xavier Giannoli which is loosely based on her story.

Set in 1920s France, Marguerite Dumont (Catherine Frot) is a rich socialite and patroness of an Academy whose membership is made up of friends and sycophants. The highlight of any soiree is an ear-splitting performance by the rich aristocrat. Neither her friends, who rely on her patronage, nor her husband (André Marcon) who needs her money for his business, are prepared to tell her the truth. When a young critic (Sylvain Dieuaide) and his anarchist friend (Aubert Fenoy) gatecrash one of her performances they are both fascinated and decide that she deserves a wider audience.

We all know someone who is tone death but the most fascinating aspect of Jenkins’ story is that she truly believed in her abilities. Frot does brilliantly to convey this in a highly believable way. There are a couple of subplots, one involving the underused Christa Theret as an aspiring singer, which feel somewhat extraneous. However, Marguerite is satire at its best. Giannoli handles the material beautifully, and does so with a knowing smile.

Marguerite is out in cinemas on Friday.