Hollywood is very fond of two things: trying to cash in on another film’s success, and playing fast and loose with historical accuracy. Which is why 300 – a film about the Battle of Thermopylae in 480BC, in which a small band of Spartans did battle against a vast invading army – is a Godsend to any savvy producer. Based on Frank Miller’s fantastic comic, it’s been shot in the exact same way as his last big hit, Sin City – on green screen, designed frame by frame to look identical to the source material. Best of all, the historical accuracy has already been thrown out of the window by Miller himself, whose comic portrays Persian king Xerxes as an 8ft-tall bondage freak, leading an army of mutants, elephants and yes, really – ninjas into battle in Ancient Greece.