Frank Miller promises the long-discussed prequel Xerxes will tell "a more complex story" than 300, his 1998 miniseries about the Battle of Thermopylae that became a 2007 box-office hit.

Officially confirmed on Tuesday by Dark Horse, the six-issue miniseries will likely debut in 2011. The publisher will release a Xerxes lithograph in October.

As Miller first revealed in December, Xerxes will take place 10 years before Thermopylae, beginning with the legendary Battle of Marathon, which marked the end of Persia's first invasion of Greece.

"The story will be the same heft as 300 but it cover a much, much greater span of time -- it's 10 years, not three days," Miller told the Los Angeles Times this week. "This is a more complex story. The story is so much larger. The Spartans in 300 were being enclosed by the page as the world got smaller. This story has truly vast subjects. The Athenian naval fleet, for instance, is a massive artistic undertaking and it dwarfed by the Persian fleet, which is also shown in this story. The story has elements of espionage, too, and it's a sweeping tale with gods and warriors."

He said that while Xerxes is the title character, the protagonist is Themistocles, the famed Athenian politician and general.

"The story is very different than 300 in that it involves Xerxes search for godhood," he told the newspaper. "The existence of gods are presupposed in this story and the idea is that he well on his way to godhood by the end of the story. [...] With Themistocles I have a character who is almost the dead opposite of Leonidas in that Themistocles was a lying, conniving, brilliant, heroic figure. He was nicknamed 'The Subtle Serpent' and he always manages to do the exact right things that will result in him benefiting greatly."

Miller also took to Twitter last night, answering a handful of questions about Xerxes, the status of Holy Terror, and more.

Asked why he decided to "go back to the well" with this miniseries, Miller replied: "Are you kidding? I get to do Ancient Greek Battle Stories!" He named 300 as the work he's most proud of, saying, "It's the best damn story I've ever gotten my hands on."

In the LA Times article, Miller addresses criticisms of his portrayal of Xerxes and the Persian army in 300: "My intent was misunderstood because in many ways '300' was a deliberate propaganda piece. When I work on a story I choose a point of view. For this story, the approach was to tell this story the way the Spartans told it around the campfire. That's the reason they were fighting against 80-foot elephants and that's why Xerxes was portrayed as much larger-than-life figure and given these traits that the Spartans would [project on to] their enemies."