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 largely covering the same extent of space as the modern geographical region. In its early period, the Roman province of Thrace was of this extent, but after the administrative reforms of the late 3rd century, Thracia's much reduced territory became the six small provinces which constituted the Diocese of Thrace. The medieval Byzantine theme of Thrace contained only what today is East Thrace. The largest cities of Thrace were: Plovdiv, Burgas, Stara Zagora, Sliven, Haskovo, Yambol, Komotini, Alexandroupoli, Xanthi, Edirne, Istanbul, Çorlu, Kırklareli and Tekirdağ. Most of the Bulgarian and Greek population are Orthodox Christians, while most of the Turkish