Has a nation ever undergone a significant attempt at rebranding?
Siam? Turkey?
Siam? Turkey?
Just considering common names, here's a few:
Burma -> Myanmar
Belgian Congo -> Congo -> ??? -> Zaire -> DRC
Persia -> Iran
South Rhodesia -> Rhodesia -> Zimbabwe
Upper Volta -> Burkina Faso
Yugoslavia -> Serbia and Montenegro
That would be the Federal Republic of Yugoslavia specifically. The much larger Socialist Federal Republic of Yugoslavia had already fallen apart by that time (1992).
Yugoslavia broke up in a civil war. I wouldn't count it as a 'rebranding' any more than British Empire -> United States.
And before (soon after WWI) it used to be officially called the Kingdom of Serbs, Croats and Slovenes.