The Kosovo War (Albanian: Lufta e Kosovës; Serbian: Косовски рат, Kosovski rat) was an armed conflict in Kosovo that lasted from 28 February 1998 until 11 June 1999. It was fought between the forces of the Federal Republic of Yugoslavia (FRY), which controlled Kosovo before the war, and the Kosovo Albanian separatist militia known as the Kosovo Liberation Army (KLA). The conflict ended when the North Atlantic Treaty Organization (NATO) intervened by beginning air strikes in March 1999 which resulted in Yugoslav forces withdrawing from Kosovo.
The KLA was formed in the early 1990s to fight against the discrimination of ethnic Albanians and the repression of political dissent by the Serbian authorities, which started after the suppression of Kosovo's autonomy and other discriminatory policies against Albanians by Serbian leader Slobodan Milošević in 1989. The KLA initiated its first campaign in 1995, after Kosovo's case was left out of the Dayton Agreement and it had become clear that President Rugova's strategy of peaceful resistance had failed to bring Kosovo onto the international agenda. In June 1996, the group claimed responsibility for acts of sabotage targeting Kosovo police stations, during the Kosovo Insurgency. In 1997, the organization acquired a large quantity of arms through weapons smuggling from Albania, following a rebellion in which weapons were looted from the country's police and army posts. In early 1998, KLA attacks targeting Yugoslav authorities in Kosovo resulted in an increased presence of Serb paramilitaries and regular forces who subsequently began pursuing a campaign of retribution targeting KLA sympathisers and political opponents; this campaign killed 1,500 to 2,000 civilians and KLA combatants, and had displaced 370,000 Kosovar Albanians by March 1999.