- John Buckler
Copais, large lake in *Boeotia, now drained, that in antiquity divided the area into two regions, the eastern and larger dominated by *Thebes (1) and the western by *Orchomenus (1). Mentioned by both Homer and Hesiod, the lake was itself divided into two basins, the north-western perhaps named Cephisis and the other Copais proper. The lake, fed principally by the *Cephissus river and some streams from Mt. *Helicon, was a basin bounded by limestone mountains. Numerous katavothra (drains) in the stone allowed water from it to drain into the northern Euboean Gulf. The lake varied in depth during the year. A shallow marsh in summer, the western part was often dry enough to be cultivated. *Aristophanes (1) notes its fame for delicious eels, fish, and reeds used to make flutes. When flooded, it left only a narrow pass between the two basins and Mt. Helicon, which proved to be strategically important, as witnessed by the numerous battles fought there.
- Ancient Geography