It was originally, tentatively called Xerxes, before it gained the longer-standing working moniker Battle Of Artemisium. Now though, Warner Bros. has finally settled on an official and permanent title for the follow-up to Zack Snyder's 300. Eva Green and Sullivan Stapleton now find themselves starring in 300: Rise Of An Empire.
The new film is once again based on a graphic novel by Frank Miller, although in this case practically no one has seen it since it's not yet published or even finished. The thrust this time though is to present the broader canvas around 300's Battle of Thermopylae, as well as the development of Rodrigo Santoro's Xerxes from common-or-garden king to the peculiar god-emperor entity we've already seen.
The titular rising empire is, we'd guess, Persia, but it could also just about refer to Greece, since this era saw the first instances of disparate states like the Athenians, Spartans and Thracians combining together against the Persians under some notion of "Greekness".
Thus, it's both a prequel to** 300**, and a, shall we say, "paralleloquel" that may move slightly beyond that film. Battle Of Artemisium (not of Artemisi_a_, as was widely mis-reported by the whole internet) was always an oddly specific title then, and the new one allows for a wider scope. Yigal Naor's presence in the film as Xerxes' father Darius strongly suggests we'll be going back to Marathon (ten years before Thermopylae), and Eva Green's Artemisia of Helicarnassus, a commander of Xerxes' fleet, was more famously at Salamis (about a month afterwards) than at Artemisium. Whatever, the carnage this time is definitely ocean-going.
Along with Green, Santoro and Naor, 300: Rise Of An Empire also stars Sullivan Stapleton as Athenian general Themistocles and Jack O'Connell as Calisto. It's directed by Noam Murro, with Zack Snyder this time acting as co-writer and producer, and is currently in production in Sofia, Bulgaria. It should be out on August 2 next year.