Traditionally, Anatolia is considered to extend in the east to an indefinite line running from the Gulf of İskenderun to the Black Sea, coterminous with the Anatolian Plateau. This traditional geographical definition is used, for example, in the latest edition of Merriam-Webster's Geographical Dictionary,[2] as well as the archeological community.[3] Under this definition, Anatolia is bounded to the East by the Armenian Highland, and the Euphrates before that river bends to the southeast to enter Mesopotamia.[3] To the southeast, it is bounded by the ranges that separate it from the Orontes valley in Greater Syria and the Mesopotamian plain.[3]
However, following the establishment of the Republic of Turkey, Anatolia was defined by the Turkish government as being effectively co-terminous with Asian Turkey. Turkey's First Geography Congress in 1941 created two regions to the east of the Gulf of Iskenderun-Black Sea line named the Eastern Anatolia Region and the Southeastern Anatolia Region,[4] the former largely corresponding to the western part of the Armenian Highland, the latter to the northern part of the Mesopotamian plain. This wider definition of Anatolia has gained widespread currency outside of Turkey and has, for instance, been adopted by Encyclopædia Britannica[5] and other encyclopedic and general reference