[makɛˈdɔnija]), officially the Republic of Macedonia (Macedonian: република македонија (help·info) , tr. Republika Makedonija), is a country located in the central Balkan peninsula in Southeast Europe. It is one of the successor states of the former Yugoslavia, from which it declared independence in 1991.outhern Serbia, including all of what is now the Republic of Macedonia, became known as the Vardar Banovina of the Kingdom of Yugoslavia. The concept of a United Macedonia was used by the Internal Macedonian Revolutionary Organization (IMRO) in the interbellum.