When Warner Bros assigned twin brothers and screenwriters Julius Epstein and Philip Epstein to adapt a stage play for the big screen in 1942, no one could have predicted the impact it would have.

Casablanca has since become one of the most recognisable and quotable films of all time, firmly embedded in Hollywood history. But what appears effortless on screen was anything but behind the scenes.

The late Leslie Epstein, son and nephew of Julius and Philip respectively, tells Louis Harnett O’Meara about the twins’ hijinks and the challenges involved in the making of an all-time classic. An Ember production.

Eye-witness accounts brought to life by archive. Witness History is for those fascinated by the past. We take you to the events that have shaped our world through the eyes of the people who were there.

For nine minutes every day, we take you back in time and all over the world, to examine wars, coups, scientific discoveries, cultural moments and much more.

Recent episodes explore everything from the death of Adolf Hitler, the first spacewalk and the making of the movie Jaws, to celebrity tortoise Lonesome George, the Kobe earthquake and the invention of superglue.

We look at the lives of some of the most famous leaders, artists, scientists and personalities in history, including: Eva Peron – Argentina’s Evita; President Ronald Reagan and his famous ‘tear down this wall’ speech; Thomas Keneally on why he wrote Schindler’s List; and Jacques Derrida, France’s ‘rock star’ philosopher.

You can learn all about fascinating and surprising stories, such as the civil rights swimming protest; the disastrous D-Day rehearsal; and the death of one of the world’s oldest languages.

(Photo: Humphrey Bogart and Ingrid Bergman in Casablanca. Credit: United Achieves via Getty Image)