Hi Historians,
I am interested in this topic and how this occurred but I have not found many resources on this topic. I did see however, a map dividing modern day "Republic of Macedonia" and surrounding neighbours with all the land given to its neighbours, such as Bulgaria, Albania, Greece etc. How did this occur and is there much information on it? Thanks in advance! DefChestan :)
The Treaty of Bucharest was in 1913, FYROM did not become an independent nation until the 1990s. It never owned any of the land partitioned in the treaty, the Macedonia region belonged to the Ottomans.
As for why these countries partitioned the land following the collapse of Turkish rule, Ottoman Macedonia was a melting pot of Greeks, Albanians, Serbs, Bulgarians, Jews, Turks, Romanians and more. There was no Macedonian race or ethnicity, it made sense for the land to be partitioned between these nations.
See the historical newspapers collected in this video: https://youtu.be/5PPl53PyDOo