Greece has long objected to the use of the name Macedonia because it was shared by the ancient Greek kingdom ruled by Alexander of Macedon, and is also used by an adjacent Greek region.
As a result of Greece’s objections Macedonia was only admitted to the UN under the provisional name of the Former Yugoslav Republic of Macedonia after it gained its independence in 1991 from the break-up of Yugoslavia.
This is one of those issues I have a strong opinion on despite not being aware of the issue five minutes ago.
Like, this is so stupid. Like, "we won't let you into our super cool club because we don't like your name" stupid. I guess the EU was doomed to failure from the beginning if we can assume that all of it's member states are bratty, petty children like Greece. Like, if you really believe that the EU is a mutually beneficial trade union, are you really going to block entry to a neighboring country over who can claim ownership of a 2500-year-dead dictator? At least Macedonia is willing to be the bigger country in the continent and change it's name so it can appease the angry infant.