The Callosians were a race native to the Outer Rim planet Callos. They developed a sophisticated culture, centered on a lifestyle of scholarship and philosophy. In 3 BBY the Galactic Empire attacked their planet and destroyed its entire ecosystem, rendering the world uninhabitable. Those who didn't perish in initial assault, were killed by extreme low temperatures of the new planet's climate. Most Callosians who were away from the planet at the time of attack defied logic and returned to their devastated homeworld, presumably to die.