Clarification:
Bulgarians were not the majority population in Dobruja at the time
Why is the region of Dobruja/Dobrugeq split in two? that's what I answer in this video.
Dobruja is a region in the east Balkans, between the Danube River and Black Sea, shared between the nations of Bulgaria and Romania. The conflict and almost conflict these two nations have had there is interesting.
Also, from now on sources will be in the description.