Inspired by reading about the Macedonian Question and its effects on the Balkans, what would be the easiest way for an independent Macedonia to be created before the Cold War? I suspect this would need a pre-1900 POD which is why I put this here.
There were a few occasions where the Great Powers discussed creating such a “free” nation but were ultimately pre-empted by the Balkan Wars. Perhaps it could be formed if a Great Power coalition had invaded the Ottomans in the late 19th century, as opposed to just Russia in the 1878 war?