These two neighbouring nations had a tumultuous history during the Middle Ages. Here are five videos examining their changing borders.
Danzig HD Mapper created this first video, which looks at the history of Bulgaria from the years 632 to 2017:
In the video ‘The Rise and Fall of the Bulgarian Empire’, Youtuber Suomi focuses just on the medieval period:
Meanwhile, Bulgaria empire mapping created this video, just focusing on the Byzantine-Bulgarian war of 913-925:
Khey Pard provides this video of Romania, which after a brief look at ancient times, begins the medieval period with the establishment of Wallachia in 1330, followed shortly afterwards by Moldova, the two states that would form Romania in the 19th century:
Khey Pard also offers this video showing the changing borders within the Balkan peninsula: