In the early 19th century, the name of Macedonia was almost unknown in the modern-day area. It was revived only in middle of the century, with the rise of nationalism in the Ottoman Empire. In the early 20th century the region was already a national cause, contested among Bulgarian, Greek and Serbian nationalists. During the interwar period the use of the name ''Macedonia'' was prohibited in the Kingdom of Yugoslavia, due to the implemented policy of Serbianisation of the local Slavic-speakers. The name ''Macedonia'' was adopted officially for the first time at the end of the Second World War by the new Socialist Republic of Macedonia, which became one of the six constituent countries of the Socialist Federal Republic of Yugoslavia. After the fall of Communism, with the beginning of the breakup of Yugoslavia, this federal entity declared independence and changed its official name to Republic of Macedonia in 1991. Prior to June 2018, the use of the name ''Macedonia'' was disputed between Greece and the then-Republic of Macedonia.