Castell was an early member of the Republic from the Colonies, but not much happened there. Though the planet was along a major trade route, it somehow managed to be dirt poor. After several requests for bailouts failed in the Senate, the Commerce Guild stepped up and purchased the planet. Things got better and eventually a Gossam, Shu Mai, moved up to become president of the Guild. After Castell suffered heavy damage in the Clone Wars, it went back to being super poor. The Empire enslaved their population. Because that's what they did.