Commander Lyle Tiberius Rourke is the main antagonist of Disney's 2001 animated feature film, Atlantis: The Lost Empire. Prior to the main events of the film, he was the Commander of a previous mission to Iceland where he assisted Milo Thatch's grandfather, Thaddeus, in locating the Shepherd's Journal. He initially appears as a very reliable and praiseworthy commander able to lead his men through perils, but as the film progresses, he turns out to be a highly manipulative, ruthless and sadistic mercenary who is out to capture the Heart of Atlantis and make money off of it.