Thessaly

Definition: Located in northern Greece, Thessaly is the largest plains area of Greece. It is almost surrounded by mountains, which are pierced by traversable valleys and passes called tempe. On the north, the Cambunian range has as its highest mountain the home of the gods, Mt. Olympus. Nearby is Mt Ossa. The Peneius River is also in Thessaly.

Thessaly is divided into 4 districts:

1. Thessaliotis,
2. Hestiaeotis,
3. Pelasgiotis, and
4. Phthiotis.

The name Thessaly comes from pastoral residents called Thessaloi, who probably come from the Balkans. They are thought to have spoken an early Greek language and had a Greek culture. The Thessaloi developed an organized federation composed of aristocratic families with an archon (chief) leading them.

Reference:

Bruno Helly "Thessaly" The Oxford Classical Dictionary.