Megalopolis, (Megalē Polis, ‘Great City’), a new foundation in SW *Arcadia in the period following *Leuctra (sources differ on the date, in the range 370–367 bce). Existing communities were combined to produce a new state with a new urban centre; five Arcadian poleis (see polis) provided *founders, but the Theban *Epaminondas is credited with strong influence. The main accounts (Diod. Sic. 15. 72. 4; Paus. 8. 27) differ on the number of communities incorporated into Megalopolis, but its territory clearly covered SW and central Arcadia, which had had no major state. The main part of the territory was a large upland basin crossed by the river *Alpheus, an area crucial for access to northern Messenia, and for travel across the Eurotas/Alpheus watershed between upper *Laconia and southern Arcadia. The new city, built in the era of liberation from Sparta, was fortified (cf.