April 1941. Creation of the NDH 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. Hitler wished to irrevocably dismantle Yugoslavia, which he dubbed a "Versailles construct". Hitler was known to be a virulent Serbophobe. He and other senior German leaders considered the Serbs to be subhuman (). Thus, in Hitler's conception of the New Order of Europe, they were to be collectively punished. Serbia was reduced to its pre-Balkan War borders, becoming the only country in the Western Balkans to be directly occupied by the Germans. 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 had been 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. Pavelić entered the NDH on 13 April and reached Zagreb two days later. The same day, Germany and Italy extended diplomatic recognition to the NDH. Pavelić assumed control and bestowed himself the title Poglavnik ("leader"). At the time of its establishment, the NDH had a population of 6.5 million inhabitants, about half of whom were Croats. It was also inhabited by nearly two million Serbs, who constituted about one-third of its total population. Lands inhabited by Serbs accounted for 60–70 percent of the NDH's total landmass. Nevertheless, Serbs – along with others whom the Ustaše deemed "undesirable", such as Jews and Roma – were denied citizenship on the basis that they were not Aryans. Within hours of the NDH's creation, businesses brandished signs reading: "No Serbs, Gypsies, Jews and dogs". Additionally, immediate measures were taken to expunge the presence of the Cyrillic alphabet from the public sphere. On 17 April, the Ustaše instituted the Legal Provision for the Defence of the People and State, a law legitimizing the establishment of concentration camps and the mass shooting of hostages in the NDH. Thirty concentration camps in total were established across the puppet state. Operation Establishment and first arrivals Đakovo, located about southeast of Zagreb, is notable as the seat of the Roman Catholic Archdiocese of