NDH) was announced over the radio by Slavko Kvaternik, a former Austro-Hungarian Army officer who had been in contact with Croatian nationalists abroad. Pavelić arrived in Zagreb on 15 April and proclaimed himself leader () of the NDH, having assured the Germans that the NDH would be loyal to the Axis cause. Disenchanted with more than twenty years of Serb hegemony, the majority of Croats enthusiastically welcomed the NDH's creation. The Axis invasion of Yugoslavia had transformed the Ustaše from a small and relatively obscure Croatian nationalist organization into a popular movement almost overnight. The Germans initially wanted to install Croatian Peasant Party leader Vladko Maček as the head of the Croatian puppet state, but Maček refused, citing his democratic convictions and his firm belief that the Axis powers would not win the war. The NDH was divided into German and Italian areas of influence. The Italian area of influence was divided into three operational zones. Zone I, which consisted of the coastal and island area surrounding the cities of Zadar, Šibenik, Trogir and Split, was directly annexed by Italy. Zone II was consigned to the NDH. It encompassed much of Dalmatia and the Dalmatian Hinterland. Zone III, also allotted to the NDH, extended as far as western and central Bosnia, a sliver of eastern Bosnia, and all of Herzegovina. 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 across the NDH. The Jewish Question was only of secondary concern to the Ustaše. Their foremost goal was to rid the NDH of its 1.9 million Serbs, who made up about 30% of the fledgling puppet state's total population. Senior Ustaše officials openly stated that they sought to kill one-third of Serbs living in the NDH, expel one-third and convert one-third to Roman Catholicism. The Ustaše movement's grievances centred around the perceived injustices inflicted upon the Croats in Serb-dominated Yugoslavia during the interwar period. Senior Ustaše officials cited the shooting of five Croatian parliamentary deputies in June 1928, the murder of the Croatian nationalist anthropologist and historian Milan Šufflay in 1931, the suppression of the Velebit uprising in 1932, the murder of the Croatian Peasant Party vice-president Josip Predavec in 1933, and the arrest and incarceration of dozens of other Croatian political figures. Initial cleansing operations In early April