Strabo Geography 8.6.25

[25] In earlier times Sicyon was called Mecone, and in still earlier times Aegiali, ¹ but Demetrius rebuilt it upon a hill strongly fortified by nature about twenty stadia (others say twelve) from the sea; ² and the old settlement, which has a harbor, is a naval station. The River Nemea forms the boundary between Sicyonia and Corinthia. Sicyon was ruled by tyrants most of the time, but its tyrants were always reasonable men, among whom the most illustrious was Aratus, ³ who not only set the city free, ⁴ but also ruled over the Achaeans, who voluntarily gave him the authority, ⁵ and he increased the league by adding to it both his native Sicyon and the other cities near it. But Hyperesia and the cities that come in their order after it, which the poet mentions, ⁶ and the Aegialus as far as Dyme and the boundaries of Eleia already belonged to the Achaeans. ⁷