At the beginning of the modern era, Southern Dobruja had a mixed population of Bulgarians and Turks with several smaller minorities, including Gagauz, Crimean Tatars and Romanians. In 1910, of the 282,007 inhabitants of Southern Dobruja, 134,355 (47.6%) were Bulgarians, 106,568 (37.8%) Turks, 12,192 (4.3%) Gypsies, 11,718 (4.1%) Tatars and 6,484 (2.4%) Romanians.
Southern Dobruja was part of the autonomous Bulgarian principality from the time of the liberation of Bulgaria from Ottoman rule in 1878 until the Balkan Wars. After the defeat of Bulgaria in the Second Balkan War, the region was incorporated into Romania under the 1913 Treaty of Bucharest. Romania ruled Southern Dobruja until 1940 settling tens of thousands of Aromanians from Macedonia and Northern Greece, as well as Romanians from Wallachia in the region.
On 7 September 1940 Southern Dobruja was restored to Bulgaria under the Treaty of Craiova. The treaty was followed by an obligatory population exchange: about 110,000 Romanians (almost 95% of which settled there after 1913) were forced to leave Southern Dobruja, whereas 77,000 Bulgarians had to leave northern Dobruja. Only a few hundred Romanians and Aromanians are left in the region to this day.