Thrace (Bulgarian: Тракия, Trakiya or "Trakija" or Trakia, Greek: Θράκη, Thráki, Turkish: Trakya) is a historical and geographic area in southeast Europe. Today the name Thrace designates a region spread over southern Bulgaria (Northern Thrace), northeastern Greece (Western Thrace), and European Turkey (Eastern Thrace). Thrace borders on three seas: the Black Sea, the Aegean Sea and the Sea of Marmara. In Turkey, it is also called Rumeli.
The historical boundaries of Thrace have varied. Ancient Thrace (i.e. the territory where ethnic Thracians lived) included present day Bulgaria, European Turkey, north-eastern Greece and parts of eastern Serbia and eastern Republic of Macedonia. Its boundaries were between the Danube River to the north and the Aegean Sea to the south, to the east - the Black Sea and the Sea of Marmara and on the west to the Vardar and Great Morava rivers. The Roman province of Thrace was somewhat smaller, having the same eastern maritime limits and being bounded on the north by the Balkan Mountains; the Roman province extended west only to the Mesta River.