Dobruja (dōˈbrŏjə, dôˈ–) [key], Rom. Dobrogea, Bulg. Dobrudza, historic region, c.9,000 sq mi (23,300 sq km), SE Europe, in SE Romania and NE Bulgaria, between the lower Danube River and the Black Sea. The chief cities are Constanţa, in Romania, and Dobrich and Silistra, in Bulgaria. Dobruja comprises a low coastal strip and a hilly and forested inland. Largely agricultural, the region grows cereal crops, has vineyards, and breeds Merino sheep. The largest industrial concentration is in and around Constanţa. Tourism is also economically important, particularly in the Romanian part of Dobruja. The population includes Romanians, Bulgarians, Turks, and Tatars. Dobruja's original inhabitants were conquered in the 6th cent. B.C. by the Greeks, who founded colonies along the Black Sea coast. The region passed to the Scythians in the 5th cent. B.C. and to the Romans (who made it part of Moesia) in the 1st cent. B.C. As part of the Roman Empire and later of the Byzantine, it suffered frequent invasions from the Goths, Huns, Avars, and other tribes. Part of the first Bulgarian empire (681–1018), it was reconquered by the Byzantines. In 1186 it was included in the second Bulgarian empire. Tatar raids were common in the 13th cent. In the 14th cent. the region became an autonomous state under Walachian prince Dobrotich, from whom the name Dobruja derives. Turks conquered the region in 1411, and for the next five centuries it remained a sparsely populated and barely cultivated territory of the Ottoman Empire. In 1878 the Congress of Berlin awarded N Dobruja to Romania and a strip of land later known as S Dobruja to Bulgaria. As a result of the second Balkan War Bulgaria ceded (1913) S Dobruja to Romania. The Treaty of Neuilly, signed in 1919 between Bulgaria and the Allies of World War I, gave all of Dobruja to Romania. In 1940, however, the German-imposed Treaty of Craiova forced Romania to transfer S Dobruja to Bulgaria.