The Balarians are humans from the planet Balar. Their people were infected by Michael with the Hoffan drug and most of the people died. The survivors left Balar and were taken in by villagers on another planet. The Wraith came to that planet and demanded that all the Balarians be delivered to them. A few of the villagers betrayed them and gave them to the Wraith but John Sheppard and his team saved them and relocated them to a new planet. (SGA: "Outsiders")