Occupying a territory of more than 300 km2, Sicyon counts among the large-size cities of Ancient Greece, yet significantly smaller to neighbouring Corinth. Its direct access to the Corinthian gulf, and its location between Corinth to the east, Achaean Pellene to the west, and the Arcadian cities of Phlius and Stymphalus to the south and the southwest, influenced the city’s trajectory from the Archaic period to the Late Roman era. Geopolitics lie behind Sicyon’s involvement with the Delphic affairs in the 6th cent, the city’s adherence to Sparta and the Peloponnesian League for almost two centuries (mid-6th to mid-4th cent. bce), its refoundation by the Macedonians at the end of the 4th cent., its connection with the Achaian Confederacy half a century later, and its predominance in the broader region after the Achaian War and the fall of Corinth. With the reestablishment of Corinth, from the 1st century ce onwards, Sicyon’s strength dwindled, and the size of the city gradually decreased, so that by the 5th century the size of the asty was reduced to less than a fifth of its original extent.