In the following spring he fastened a quarrel upon Potidaea, a town in Chalcidice, which was attached by ancient bonds to Corinth, and in the campaign which followed Athenian and Corinthian troops came to blows.
Potidaea, a Dorian town on the western promontory of Chalcidice in Thrace, a tributary ally of Athens - to which however Corinth as metropolis still sent annual magistrates - was induced to revolt,' with the support.
Corinth however had not only strong, but also immediate and urgent reasons (Potidaea and Corcyra) for desiring war.
Potidaea to Corinth).
This outrageous demand was followed by three others - that the Athenians should (I) withdraw from Potidaea, (2) restore autonomy to Aegina, and (3) withdraw the embargo on Megarian commerce.
In the winter Potidaea capitulated, receiving extremely favourable terms.
In the Achaean League the name is given to ten elective officers who presided over the assembly, and Corinth sent "Epidemiurgi" every year to Potidaea, officials who apparently answered to the Spartan harmosts.
With this end in view he established colonies at Potidaea and Apollonia in Macedonia, at Anactorium and Leucas in north-western Greece, and he is said to have projected a canal through the Isthmus, In Greece proper he conquered Epidaurus, and with the help of his fleet of triremes brought the important trading centre of Corcyra under his control, while his interest in the Olympian festival is perhaps attested by a dedication which may be ascribed to him - the famous "chest of Cypselus."
Meanwhile he had destroyed Potidaea Philip. and founded Philippi.