Seven years on and a new chapter of this epic saga has arrived. It boasts just as much, if not more, blood, brutality and buff flesh as 300.
After award-winning commercial director Noam Murro was chosen to helm the project, focus turned to casting.
Australian actor Sullivan Stapleton was picked to play general Themistocles, part-soldier, part-politician.
"Whereas Leonidas rules Sparta in a very authoritative, military style, Themistocles must be a great speaker to rally all of Greece to fight as one," says the 36-year-old.
His formidable adversary is Artemisia (Eva Green), who Murro asserts "is also driven but her brutality is born of vengeance".
French actress Green, who came to prominence as Daniel Craig's doomed love interest in Casino Royale, savoured the opportunity to don an array of vampish costumes while carrying out unspeakable acts, like kissing the lips of a man she's just decapitated.
"I love playing evil characters, but especially those who are complex and have a reason to behave in such a way. It's always more interesting," says Green, 33. "What I like about her is that she's utterly fearless. Her tragic flaw is her obsessive need for revenge."
Although she was able to do some research on the real Artemisia, the character in the film is "quite a bit different", Green notes. "But then a woman commander all those years ago was rather unusual, so she had to have been exceptionally strong."
The actress threw herself into training, admitting she's "not the most co-ordinated" person.
"It was a bit scary in the beginning," she recalls.
While fighting with two swords was a big challenge, Green says the stunt team on the film were "the best ever".
"It was so much fun. I felt like I was living my dream," she concludes.
But perhaps the most daunting task fell to the actors who had to appear on screen as if no time had passed, like Rodrigo Santoro, who reprises his role as Xerxes, the God-King.
The process to look the part "was as intense as the first one - hours and hours in the gym and months without ice cream or chocolate".
"But that's the price you pay to be a God-King," adds the Brazilian star, grinning.