At first I thought: Oh the poor Greeks and their inferiority/superiority complex. And where did Alexander the Great coem from. Well actually, the Greeks have it right. The ancient kingdom of Macedon, led by Alexander The Great’s father, and was known sometimes as the Macedonian Kingdom was mostly in what is now northern Greece, until it conquered all of Greece. Modern Macedonia, now “North Mecedonia” WAS north Macedon & the center of from where Phillip and Alexander ruled.
The Greeks of the 5th and 4th centuries B.C. did not think much of the Macedonians and some sources call them barbarians--the use of Greek was widespread up there (Euripides died at the court of the king of Macedonia), but whether the native Macedonian language was a dialect of Greek or a separate (but related) language is debated--insufficient ancient evidence. Modern Greeks, of course, claim that the ancient Macedonians were Greek. Much of the Greek population of modern Macedonia is descended from Greeks who fled from Turkey in the 1920s.