La Grande Illusion is probably one of the greatest anti-war films ever made. Based on director Jean Renoir’s own experiences as a prisoner of war during World War I, the film concerns two French officers (Pierre Fresnay and Jean Gabin) who become the prisoners of an aristocratic Prussian officer (Erich von Stroheim) after being shot down over Germany. Holed up in a mountain fortress chateau, the two men then plot their daring escape with their help of their new comrades.

Released on the eve of World War II in June 1937, the film was banned in Germany and Italy, but ended up becoming a great international success for the director. And it’s easy to see why. Its power and drama – even 75 years after its original release – comes not from its strong anti-war message, but from the personal relationships that develop between the captured soldiers, which transcend class, religion and nationality.

This is especially highlighted in Jean Gabin’s character, a working class lieutenant who forges a friendship with a wealthy French Jew (Marcel Dalio), which was something of a political statement in its day; and in the solidarity of the upper classes (as represented by Fresnay and Stroheim), despite their country of origin.

Highly praised by critics and film historians alike, the film famously inspired the La Marseillaise scene in 1942’s Casablanca – as well as many other wartime escape dramas – and remains a defining moment in French cinema. On 6 April, a brand new digital restoration of the film – overseen by StudioCanal and La Cinémathèque de Toulouse – will be screened in UK cinemas, ahead of its DVD and Blu-ray