Yugoslavia was quickly overwhelmed by the combined strength of the Axis powers and surrendered in less than two weeks. The government and royal family went into exile, and the country was occupied and dismembered by its neighbours. Serbia was reduced to its pre-Balkan War borders and directly occupied by Germany. Serb-inhabited territories west of the Drina River were incorporated into the Axis puppet state known as the Independent State of Croatia (; NDH), which included most of modern-day Croatia, all of modern-day Bosnia and Herzegovina, and parts of modern-day Serbia. The establishment of the NDH was announced over the radio by Slavko Kvaternik, a former Austro-Hungarian Army officer who had been in contact with Croatian nationalists abroad, on 10 April.