Thessaly (Θεσσαλια; modern Greek Thessalía) is one of the 13 peripheries of Greece, and is further sub-divided into 4 prefectures. The capital of the periphery is Larissa. The prefecture lies in central Greece and borders Macedonia on the north, Epirus on the west, Sterea Hellas or Central Greece on the south and the Aegean Sea on the east.
Its geography consists of a ring of mountains surrounding a central plain: Trikala and Larissa lowlands. It has a distinct summer and winter season, with summer rains augmenting the fertility of the plains. This has led to Thessaly occasionally being called the breadbasket of Greece.
The region is well delineated by topographical boundaries. The Khásia and Cambunian mountains lie to the north, the Olympus massif to the northeast. To the west lies the Pindus mountain range, to the southeast the coastal ranges of Óssa and Pelion.
Several tributaries of the Piniós River flow through the region.
There are a number of highways and the main railway from Athens to Thessaloniki (Salonika) crosses Thessaly.
Thessaly was home to an extensive Neolithic culture around 2500 BC. Mycenaean settlements have also been discovered, for example at the sites of Iolcos, Dimini and Sesklo (near Volos). Later, in ancient Greek times, the lowlands of Thessaly became the home of baronial families, such as the Aleuads of Larissa or the Scopads of Crannon. These baronial families organized a federation across the Thessaly region, later went on to control the Amphictyonic League in northern Greece. The Thessalians were renowned for their cavalry.
During the Greco-Persian Wars the Aleuads joined the Persians. In the 4th century BC Thessaly became dependent on Macedonia and many served as vassals. In 148 BC the Romans formally incorporated Thessaly into the province of Macedonia, but in AD 300 Thessaly was made a separate province with its capital at Larissa.
Between the 7th and the 13th century the area was controlled by Slavs, Byzantines, Bulgars and Normans. However by the 13th century Thessaly came to be called Megale Vlachia (Great Walachia) and was controlled by Vlach herdsmen. In 1394 the Turks assumed rule. In 1881 Turkey ceded most of Thessaly to Greece.
Thessaly is divided into 4 prefectures: