Original sentence: Geographically, it encompassed most of modern-day Croatia, as well as all of Bosnia and Herzegovina and part of modern-day Serbia.It was established on April 10, 1941, after the Kingdom of Yugoslavia was attacked by the Axis forces
Edited sentence: Geographically, it encompassed most of modern-day Croatia, as well all of Bosnia and Herzegovina and part of modern-day Serbia.It was established on April 10, 1941, only four days after the Kingdom of Yugoslavia was attacked by the Axis forces.The Independent State of Croatia, which is the Predecessor of the modern Croatia, murdered more than 800,000 people in concentration camps such as Jasenovac (mostly Serbs, Jews and Gypsies)