The area, which is today's former Yugoslav Republic of Macedonia (FYROM) lies to the north of Hellenic Macedonia. Nowadays its southern border runs along the modern Greek province of Macedonia.
Greece claims the name Macedonia - and its ancient legacy, including that of its greatest ruler, Alexander the Great - for its northernmost province and accuses Skopje of showing territorial aspirations and stealing history by taking it for the country.
Ever since Macedonia emerged from the disintegrating Yugoslavia in 1991, Athens has blocked Skopje internationally, only allowing it to join the United Nations under the name FYROM.
In June, after 27 years of diplomatic wrangling, the neighbors struck an agreement to rename FYROM as the republic of Northern Macedonia.
The agreement needs to be ratified through a series of steps on both sides of the border. Only then will Athens lift diplomatic obstacles.
Macedonia was a Greek kingdom which peaked during the 4th century BC reign of the nearly mythical Alexander the Great, one of the best-known rulers of the classical Hellenic era.
A son of another prominent king, Philip II, in just 33 years of life and 13 of rule, Alexander conquered a vast territory, stomping through rival Hellenic kingdoms. He also sent his forces through the Persian empire to reach India in the east and Egypt to the south.
To the north, his father had already conquered Paeonia, an ancient kingdom of raiders which lay on the territory of the modern Macedonia and western Bulgaria.
Paeonians were of Thracian, or Illyrian, origin, or a mix of the two, but not Hellenic, or Greek, and their language has gone extinct.
After the 3rd century BC, the former Paeonian territory was later ruled for centuries by the Roman, then the Byzantine Empire, as well as the Slavs - Bulgarians and Serbs - after their arrival in 6th century. In the 14th century, the Ottomans conquered the region as they spread north across the Balkans and remained there for the next five centuries.
The idea of an autonomous Macedonia began emerging in the late 19th century, contributing to the birth of the Macedonian Revolutionary Organization (MRO) in 1904, the predecessor of the Internal Macedonian Revolutionary Organization (VMRO).
The party was initially open only to Bulgarians, later to all non-Ottomans.
When the kingdom of Yugoslavia was established after World War I, the territory of Macedonia was named Vardar Banovina, or Vardar district, after its largest river. In late 1920s, Belgrade crushed an insurgency of pro-Macedonian guerrillas.
The increasingly influential international Communist organization, the Comintern, began propagating the idea of Macedonia and Macedonian as an autonomous state and language in mid-1930s.
The Communist-led authorities proclaimed the People's Republic of Macedonia as a part of the federal People's Republic of Yugoslavia in 1944, during World War II.
With that, the seed was sown for the emergence of the independent Republic of Macedonia once Yugoslavia fell apart.