Thrace Europe. The word "Thrace" was established by the Greeks for referring to the Thracian tribes, from ancient Greek Thrake (Θρᾴκη), descending from "Thrāix" (Θρᾷξ). The name of the continent Europe first referred to Thrace proper, prior to extending its meaning to the whole continent. The region could have been named after the principal river there, Hebros, possibly from the Indo-European "arg" "white river" (the opposite of Vardar, meaning "black river"), . According to an alternative theory, Hebros means "goat" in Thracian. In Turkey, it is commonly referred to as "Rumeli", "Land of the Romans", owing to this region being the
Thrace (theme) Krum (r. 803–814), Omurtag (r. 814–831), and Symeon (r. 893–927) the border moved by stages south of the Balkan mountains to roughly the line of the present Bulgarian frontier with Greece and Turkey. Thus, at around the start of the 10th century, the theme comprised essentially the eastern half of modern Eastern Thrace, although it extended north along the coast to include Anchialos. From the 11th century, Thrace and Macedonia appear to have been usually combined, as attested by numerous "strategoi" and judges ("kritai") holding jurisdiction over both themes. The name fell out of use as an administrative term in