East Thrace the Turkish Straits) and the Sea of Marmara, a route of about 361 km. The southernmost part of Eastern Thrace is called the Gallipoli peninsula. European Turkey is bordered on the west by Greece for 212 km and on the north by Bulgaria for 269 km, with the Aegean Sea to the south-west and the Black Sea to the north-east. East Thrace was the setting for several important events in history and legend. The mass killings and displacement of Thracian Bulgarians in 1913 and the 1923 population exchange between Greece and Turkey ethnically cleansed the Orthodox populations. Prior to that
Thrace (theme) the Palaiologan period, but it is still encountered in some historians of the time as an antiquarian term. Thrace (theme) The Theme of Thrace () was a province ("thema" or theme) of the Byzantine Empire located in the south-eastern Balkans, comprising varying parts of the eponymous geographic region during its history. Traditionally, it has been held that the theme (at the time primarily a military command) was constituted in c. 680, as a response to the Bulgar threat. This is based on the mention of a certain "patrikios" Theodore, Count of the "Opsikion" and "hypostrategos" of Thrace, in 680/681. However,