There is an official page for this soundtrack www.alexandersoundtrack.com/
From that site:
Oscar-winning Greek composer Vangelis is creating the original score for Oliver Stone's Alexander, an epic retelling of the story of the legendary Greek conqueror-hero Alexander the Great, with Colin Farrell in the title role. An Intermedia film in association with IMF with a cast that includes Academy Award winners Angelina Jolie and Sir Anthony Hopkins as well as Val Kilmer, Jared Leto, Rosario Dawson and Jonathan Rhys-Meyers, Alexander opens nationwide from Warner Bros. on Wednesday, November 24, 2004. Sony Classical will release the film's original soundtrack recording on Tuesday, November 9, 2004.