Ancient city, northern Peloponnese , southern Greece.
Located 11 mi (18 km) northwest of Corinth , Sicyon was influential in Greek history, attaining its greatest power in the 6th century BC under Cleisthenes, grandfather of Cleisthenes of Athens . During the 4th century BC it was celebrated for its school of painters and sculptors, which included Lysippus . In the 3rd century BC it gained prominence under Aratus , who brought it into the Achaean League .