Fact One: How come all the Jedi have first and second names except Yoda? We have Obi-Wan Kenobi, Anakin Skywalker, Mace Windu and Qui-Gon Jinn, among others, but Yoda's just Yoda. In fact, his full name - never revealed in the films - is Minch Yoda. Lucas deliberately decided to leave him with just one name to enhance the air of mystery and power around him.

Fact Two: Sound effects supremo Ben Burtt couldn't find a suitably sci-fi sound effect for the iconic lightsabres, until he accidentally walked past a muted TV while holding a microphone. He mixed the resulting low hum with the sound of a film projector motor and the rest was history. Additionally, Burtt ran his hands through cheese casserole to create the sound of Jabba's slither, sampled a car window motor for R2-D2's movements and recorded an Asian sea otter for the sound of the Tauntauns.

Fact Three: Though you wouldn't know it watching any recent copies of the Star Wars series, Emperor Palpatine was originally played by an elderly female stand-in, with chimpanzee eyes superimposed over her face to make her look creepy. Only when it came to casting The Emperor (who is never mentioned by his name throughout the original trilogy) in Return Of The Jedi did Lucas cast Ian McDiarmid, who also recorded inserts for the Special Edition DVD re-releases. So long, lady!

Fact Four: In the original trilogy, the sound of Darth Vader breathing was initially intended to be far wheezier and more laboured than the end result. In fact, if you're curious to know how it would have sounded, watch the end of Return Of The Jedi, when Vader is left battered and dying. His breathing there was recorded for the first film and discarded in favour of a smoother breathing sound.

Fact Five: All Star Wars fans know Chewie is a Wookiee. But did you know the word 'Wookiee' originated on a previous George Lucas film? In sci-fi THX 1138, when the hero steals a car, you can hear a voice on the police radio saying, "I ran over a Wookiee back there on the expressway". This ad-lib by voiceover artist Terry McGovern stuck with George and inspired him while writing Star Wars.

Fact Six: Did you know that Chewbacca - thanks to a very silly error - never actually got to sit in the Millennium Falcon cockpit? When it was built, the set designers hadn't factored in the sheer size of Chewy actor Peter Mayhew, who turned up on the morning of the shoot and realised he literally couldn't fit into his seat. Thanks to the magic of editing, the big hairy lunk was inserted into these scenes afterwards.