The potential for disaster was there from the beginning. The novel it was based on, by Margaret Mitchell, was a runaway bestseller – but it was also 1,037 pages long. David O Selznick, an independent producer, paid $50,000 for the film rights, but the task of turning the book into a screenplay was so perplexing that it was never actually completed. The script was written and rewritten countless times over the following years, by F Scott Fitzgerald among many others, but Selznick himself kept revising the dialogue every day while the film was in production. Shooting such a lengthy and complicated film was even more difficult. Selznick screen-tested 31 of America’s most popular actresses for the lead role, before settling on Leigh, a relatively unknown Brit. He hired his friend, George Cukor, to be the director, only to replace him with Victor Fleming after three weeks of shooting. Fleming, in turn, had a nervous breakdown, and abandoned the project for two weeks. As the budget spiralled, Gone with the Wind became known in the gossip columns as ‘Selznick’s folly’.

‘Fast and frivolous’

That all changed when it was finally released. An immediate smash hit, it went on to win 10 Oscars and become the most lucrative film of the year. Selznick’s perfectionism was vindicated – as was his habit of popping Benzedrines so he could keep working for days on end without sleep. But this triumph was by no means a sure thing. Audiences who fell for the film could easily have been baffled instead.

Gone with the Wind doesn’t start out as a blood, sweat and tear-stained historical epic, but as a cheeky, sun-dappled romantic comedy. Scarlett O’Hara (Leigh) is introduced flouncing around in a dress like a frilly parachute, trilling “fiddle-dee-dee!” and fending off twin red-headed suitors. The Civil War is on the horizon, but the antebellum South is presented as “a whole world that wants only to be graceful and beautiful”. And Scarlett doesn’t care about anything except that the man she has her eye on, Ashley Wilkes (Leslie Howard), is engaged to his goody-goody cousin Melanie (Olivia de Havilland). Not even the attentions of the rakish Rhett Butler (Gable) can distract her.

The film’s next surprise is that even when the Civil War commences, the tone remains as fast and frivolous as ever. The death of Scarlett’s first husband is treated as a joke: there’s a quick shot of a letter announcing that he has died of measles, and then Scarlett is seen trying on hats to go with her widow’s weeds. In general, it’s astonishing how speedy this four-hour film is. A constant barrage of dramatic upheavals ensures that you never catch your breath, and the editing is so nimble that you hardly catch a glimpse of any of Scarlett’s three weddings. At a time when The Hobbit can account for three films and The Hunger Games: Mockingjay can cover two, it’s impossible to imagine a 21st-Century movie dealing with the same material so snappily.

‘Ridiculous love triangle’

After that sprightly first hour, though, Scarlett is engulfed in the Civil War, and the mood turns very dark indeed. Viewers who had been enjoying the farcical romantic shenanigans could well have been appalled by the unsparing scenes of her traumatic nursing work (which are echoed in Joe Wright’s Atonement and the forthcoming Testament of Youth). And then there’s Scarlett herself: ruthless in her manipulation, psychopathic in her determination, and strikingly modern in her social impropriety. Few heroines in cinema history are quite as unorthodox.