Balkans Regions in May of 1990 just before the onset of the Fourth Balkan War. The Federation of Yugoslavia, backed by western allies such as France and the United Kingdom as well as regional powers such as the Romanian Federal Republic and Republic of Hungary, would repel large areas of land held by the communist Free People's Democratic Socialist Republic of Aegean States. The war, the deadliest since the end of WWII, would see the liberation numerous Serb and Romanian towns, the beginning of mass ethnic cleansing on part of both sides of the war, stopping only with the signing of the Treaty of Milan in August of 1995. An estimated 600,000 people were killed in armed combat, a further 200,000 in the ethnic cleansings and the displacement of nearly 1,000,000 peoples in the aftermath of the war.
Several years later, strained and facing numerous internal rebellions, the FPDSRAS would dissolve into three new states (People's Republic of the Aegean, Republic of Bulgaria and the Republic of Macedonia) and cede large amounts of territory to Yugoslavia, Romania and Republic of Turkey. Tensions between the three new states would boil over into the Fifth Balkan War in 2001.