Southern Dobruja
Southern Dobruja, South Dobruja or Quadrilateral (Bulgarian: Южна Добруджа, romanized: Yuzhna Dobrudzha or simply Добруджа, Dobrudzha; Romanian: Dobrogea de Sud, Cadrilater or Dobrogea Nouă) is an area of north-eastern Bulgaria comprising Dobrich and Silistra provinces, part of the historical region of Dobruja. It has an area of 7,412 square km[1] and a population of 358,000. It was a part of the Kingdom of Romania de jure from 1913 to 1918 (de facto from 1913 to 1916) and again from 1919 to 1940.