Thessaly (Greek: Θεσσαλία, Thessalía — Thessalian: Πετθαλία, Petthalia) is a traditional geographical region and an administrative region of Greece, comprising most of the ancient region of the same name. Before the Greek Dark Ages, Thessaly was known as Aeolia, and appears thus in Homer's Odyssey.
Thessaly became part of the modern Greek state in 1881, after four and a half centuries of Ottoman rule. Since 1987 it has formed one of the country's 13 regions and is further (since the Kallikratis reform of 2010) sub-divided into 5 regional units and 25municipalities. The capital of the region is Larissa. Thessaly lies in central Greece and borders the regions of Macedonia on the north, Epirus on the west, Central Greece on the south and the Aegean Sea on the east. The Thessaly region also includes theSporades islands.