Thessaly or Thessalia (Attic Greek: Θεσσαλία, Thessalía or Θετταλία, Thettalía[1]) was one of the traditional regions of Ancient Greece.

During the Mycenaean period, Thessaly was known as Aeolia, a name that continued to be used for one of the major tribes of Greece, the Aeolians, and their dialect of Greek, Aeolic.

At its greatest extent, ancient Thessaly was a wide area stretching from Mount Olympus to the north to the Spercheios Valley to the south.

Thessaly is a geographically diverse region, consisting of broad central plains surrounded by mountains.

The Pagasetic Gulf in southeastern Thessaly was and is the only body of water suitable for harbours in the region.

Strictly speaking, Thessaly refers primarily to the central plains inhabited by the Thessalians in antiquity.

The plains were divided into four administrative regions called tetrads: Pelasgiotis, Phthiotis, Thessaliotis, and Histiaeotis.

The perioikoi were composed of Perrhaibia, Magnesia, Achaea Phthiotis, Dolopia, Ainis, Malis, and Oitaia.

Thessaly was home to extensive Neolithic and Chalcolithic cultures around 6000 BC–2500 BC (see Cardium pottery, Dimini and Sesklo).

Ancient tribes in Thessaly mentioned by Homer or other poets were: Aeolians, Magnetes, Perrhaebi and Pelasgians.

The name of Thessaly recorded epigraphically in Aeolic variants *Πετταλία, Πετθαλία, Φετταλία, Θετταλία.

Under the guidance of leaders, who are said to have been descendants of Heracles, they invaded the western part of the country afterwards called Thessaly, and drove out or reduced to the condition of Penestae, or bondsmen, the ancient Aeolian inhabitants.

[2] Afterwards, the Thessalians spread over the other parts of the country, taking possession of the most fertile districts and compelling the Peraebi, Magnetes, Achaean Phthiotians and other neighbouring people to submit to their authority and to pay them tribute.

Under one of these princes, named Aleuas, the country was divided into four districts – Phthiotis, Plistiaeotis, Thessaliotis and Pelasgiotis:[5] This division continued throughout Thessalian history, and it may therefore be concluded that it was not merely a nominal one.

[6] When occasion required, a chief magistrate was elected under the name of tagus, whose commands were obeyed by all four districts.

[7] The tribute Jason levied from the subject towns was the same as had been previously paid by one of the Scopadae family, whom Buttmann supposes to be the same Scopas as the one mentioned by Aelian ( V. H. xii.

The different cities administered their own affairs independently of one another, though the smaller towns seem to have frequently "been under the influence of the more important ones (Xenoph.

At Pharsalus too at the close of the Peloponnesian War, the state was torn asunder by internecine commotions and, for the sake of quiet and security, the citizens entrusted the acropolis and the whole direction of the government to Polydamas of Pharsalus, who discharged his trust with the strictest integrity.

(See Thorax of Larissa, Thargelia (hetaera)) However, the power of the aristocratical families seems to have continued with little diminution until towards the close of the Peloponnesian War, when decidedly democratic movements first begin to appear.

At Pherae, a tyranny, probably arising from a democracy, was established by Lycophron, who opposed the great aristocratical families and aimed at the dominion of all Thessaly.

The latter object was accomplished by Jason of Pherae, the successor, and probably the son, of Lycophron, who effected an alliance with Polydamas of Pharsalus and caused himself to be elected tagus about in 374 BC.

While he lived, the whole of Thessaly was united as one political power but, after his murder in 370 BC, his family was torn asunder by internecine discords and did not maintain its dominion for long.

The office of tagus became a tyranny under his successors, Polydorus, Polyphron, Alexander, Tisiphonus, and Lycophron; until, at length, the old aristocratical families called in the assistance of Philip II of Macedon, who deprived Lycophron of his power in 353 BC, and restored the ancient government in the different towns.

The Thessalian people elected Philip archon tagus of the Thessalian League for life; a few years later (344 BC), he re-established the tetrarchies (or tetradarchie), installing governors devoted to his interests and who were probably members of the ancient noble families.

At the close of the First Macedonian War, 197 BC, under Flamininus, it was declared free along with Orestis;[8] but ultimately it was incorporated in the Roman province of Macedonia along with Epirus vetus.