 Periander built Corinth into one of the major trading centers in Ancient Greece.He established colonies at Potidaea in Chalcidice and at Apollonia in Illyria, conquered Epidaurus, formed positive relationships with Miletus and Lydia, and annexed Corcyra, where his son lived much of his life.Periander is also credited with inventing a transport system, the Diolkos, across the Isthmus of Corinth.