Military operations in
World War II on the territory of
Yugoslavia started on 6 April 1941, when the
kingdom was
swiftly conquered by Axis forces and partitioned between
Germany,
Italy,
Hungary,
Bulgaria and client regimes. Subsequently, a guerrilla
liberation war was fought against the
Axis occupying forces and their locally established puppet regimes, including the
Independent State of Croatia and the
Government of National Salvation in Serbia, by the
Communist-led republican
Yugoslav Partisans. Simultaneously, a multi-side
civil war was waged between the Partisans, the Serbian royalist
Chetniks, Croatian nationalist
Ustaše and
Home Guard, as well as
Slovene Home Guard troops.