Humanoid species with a centuries-long history of conflict and hatred with the Denobulans, explored through Doctor Phlox's encounter with the Antaran patient Hudak.
The Antarans and the Denobulans fought each other for centuries, and although open conflict had ended long before Enterprise's time, bitterness remained on both sides. The two peoples had had almost no contact for generations.
In The Breach, Enterprise rescued refugees from a damaged transport, among them the gravely irradiated Antaran Hudak, who refused to let a Denobulan treat him. Phlox respected his wishes until he found a way to change Hudak's mind, revealing his own past prejudice, and the two men took a small step toward reconciliation.