Invasion of Yugoslavia

The Invasion of Yugoslavia, also known as the April War or Operation 25, was the Axis invasion of Kingdom of Yugoslaviaball by the Axis Powers, mainly  Nazi Germanyball,  Kingdom of Italyball, and  Kingdom of Hungaryball in April of 1941. It was part of the Balkans Campaign of World War II and ended in an Axis victory, but it devolved into a guerrilla war not long afterwards.

History
The Kingdom of Italy, a member of the axis powers had invaded the The Kingdom of Greece. Adolph Hitler, leader of the Third reich had to help its ally fight off Greece. So he formed the Tripartite pact along with The kingdom of Hungary,  The kingdom of Romania and the  The kingdom of Bulgaria. The Kingdom of Yugoslavia was pressured to join, but it was hugely unpopular with the Serbs leading to a coup.

Adolph Hitler was angered by the coup and ordered the Luftwaffe to bomb the city of Belgrade to ruins. The Kingdom of Yugoslavia was then annexed by the the third reich. However, two Guerrilla fighting groups emerged from the ruined Yugoslavia. These rebels were The Chetniks (Originally the Royal Yugoslav army) a Serbian Orthodox group aiming to restore the Monarchy of Yugoslavia, and the  Yugoslav Partisans, a communist group aiming to start a socialist state.