Macedonia, ancient name of part of northern Greece. The Macedonia of Herodotus was bounded on the east by the river Lydias and the Thermaean Gulf, on the south by Thessaly, on the west by Mount Pindus, and on the north by Mount Lyncestus. Philip's kingdom originally extended to the Strymon on the east, but did not include the Thracian Chersonese. He added that Chersonese and the district between the rivers Strymon and Nestus, Paeonia on the north, and on the west part of Illyria as far as Lake Lychnitis and the river Drilo. Under Alexander Macedonia became the most powerful state in the world. The Roman province of Macedonia (B.C. 166) included Illyria and Thessaly and Thrace as far towards the east as the river Hebrus (Maritza).