Southern Dobruja (Dobrudzha in Bulgarian, Dobrogea de sud or Cadrilater in Bulgaria comprising the two former administrative districts named for its two principal cities of Dobrich and Silistra. It has an area of 7565 kmē and a population of 358,000.
History
First joined to modern Bulgaria at its restoration as a state in 1878, it was a part of Romania from 1913 until 1940. In 1940, the Nazi Germany imposed Romania in the Treaty of Craiova to cede it to Bulgaria with a population exchange (the Romanian minority was forced to leave the south while the Bulgarian minority had to leave the north).
In reversing a major element of the Treaty of Trianon, it, like Trianon, granted a multiethnic area to another country, caused massive migration of populations from both sides, and sundered old socioeconomic units.
Besides the Second Vienna Award as such, on September 7, under the Treaty of Craiova, the Cadrilater or "Quadrilateral" (southern Dobrudja) was returned by Romania to Bulgaria.
This territory had been part of Bulgaria from 1878 to 1913, at which time it had become part of Romania after Bulgaria's defeat in the Second Balkan War.