Over more than half a century, Jean-Pierre Léaud has had a profound influence on French cinema. He’s arguably the most important actor of his generation. He first came to notice as a child as the star of François Truffaut’s masterpiece 400 Blows. He excelled in some of Truffaut’s best films and worked with some of the greatest European directors (including Godard, Rivette, Pasolini, Bertolucci and Kaurismäki). However, his best performance is arguably in Albert Serra’s new film The Death of Louis XIV.

In the summer of 1715, Louis XIV (Léaud) feels a pain in his leg whilst out walking. He carries on as normal but finds himself coming down with a fever and having increasingly troubled sleep. He loses his appetite and becomes weak. At the insistence of his physician (Patrick d’Assumçao), Louis spends most of his time in bed. Cloistered with his closest advisors and doctors, in hushed tones they frantically discuss their options.

The Death of Louis XIV is a slow-burning character study of France’s greatest king. Based on the memoirs of the Duc de Saint-Simon, Serra portrays a group of men scared for the future and unable to solve a problem medical science had yet to understand. What could have easily have been a damp squib is rendered compelling by Léaud’s performance. Every movement, every facial expression, speaks volumes. The Death of Louis XIV is a beautifully constructed period drama. A treatise on mortality.

The Death of Louis XIV is out in cinemas from Friday.