Czechoslovakia didn't change it name, it split up. Same could be said for Yugoslavia, but I think there was a name change from (already much split-off) Yugoslavia to (now further split-up) Serbia and Montenegro
Ancient Macedonians were an ancient Greek tribe.The name Macedonia is of Greek origin derives from the word Makednos (Μακέδνος) which means tall. Alexander The Great was the king of the ancient Greek kingdom of Macedonia.He's name is also of Greek origin and derives from the words Alexein (Αλέξειν) and aner (ανήρ) which means ''Defender of the people''. We,call Macedonia for hundrends of years now the region of the northern Greece where Thessaloniki (2nd biggest city in Greece), Kavala, Serres, Kozani, Drama, Kilkis,etc. Now the people of Fyrom are trying to take all those things and make it like it is theirs. They claim everything to be theirs. But plenty of scientists will say that Macedonia was undoubtedly Greek. And also calling those people Macedonians is offensive not only to all the Greeks but to people that live in the Macedonia region in Greece and call themselves Macedonians for hundreds of years now. And also Tito plays a big part on this but this is a story for another time
Macedonia officially changed their name to North Macedonia WITH GREEK RECOGNITION yesterday (6/17/18). so it should be added. and the UN recognized eSwatini as Swaziland's new name. that should be added as well.