Inhabited since paleolithic times, it has been under the political, cultural and linguistic influence of the Greek world since the classical era;[2][3] Greeks from the Aegean islands extensively colonized the region (especially the coastal part) and built prosperous cities such as Abdera (home of Democritus, the 5th-century BC philosopher who developed an atomic particle theory, and of Protagoras, a leading sophist) and Sale (near present-day Alexandroupolis).
The Romani of Thrace are also mainly Muslim, unlike their ethnic kin in other parts of the country who generally profess the Orthodox faith of the Greek majority.
At the beginning of the 2nd AD century Roman emperor Trajan founded here, as a part of the provincial policy, two cities of Greek type (i.e. city-states), Traianoupolis and Plotinopolis.
From this region passed the famous Via Egnatia, which ensured the communication between East and West, while its ramifications were connecting the Aegean world with Thracian hinterland (i.e. upper and middle valley of Evros river).
During the great crisis of the Roman Empire in the 3rd century AD, Western Thrace suffered from the frequent incursions of the barbarians until the reign of Diocletian, when it managed to prosper again thanks to its administrative reforms.
During Ottoman rule, Thrace had a mixed population of Turks and Bulgarians, with a strong Greek element in the cities and the Aegean Sea littoral.
In late April 1920, as per the San Remo conference which gathered the leaders of the main allies of the Entente powers (except the US), Western Thrace was given to Greece.
This was followed by the large-scale Greek-Turkish population exchanges of 1923 (Treaty of Lausanne), which finalized the reversal of Western and Eastern Thrace region's pre-Balkan War demography.
After the German invasion (April 1941), the area was occupied by Bulgarian troops, as part of the triple Axis occupation of Greece, during World War II.
During this period (1941–1944) the demographic distribution was further changed, with the arrest of the region's approximately 4,500 Jews by the Bulgarian police and their deportation to death camps administered by Germany.
In his 7 December 2017 visit to Greece Turkish President Recep Tayyip Erdoğan, acknowledged for the first time the multi-ethnic nature of the Western Thracian Muslim minority.
[citation needed] A number of estimates and censuses during the 1912-1920 period gave the following results about the ethnic distribution of the area that would become known as Western Thrace:[13] The Pomak population depending on the source was sometimes counted together with the Turks (Muslims) following the Ottoman system of classifying people according to religion, while in other occasions was specified separately.