The Flynn family lived on the desert planet Tatooine during the Imperial Era. Around this time, Linda Flynn-Fletcher gave birth to a newborn son Phineas Flynn. Unfortunately, Candace left the family and joined the Galactic Empire shortly after, and was never heard of again by the rest of the family. For a while, Phineas grew up without a sister.
Sometime after Candace's disappearance, Linda remarried to a new husband Lawrence Fletcher. Lawrence had a son of his own prior to the marriage Ferb Fletcher.