to the north-eastern boundary of the district of Dvor (south-west of Kostajnica) the boundary coincides with the boundary ... of the Sava Banovina. Population The population of the Vrbas Banovina in 1931 was 1,037,382. Most numerous religious groups were Eastern Orthodox Christians with 600,529 (58%), then Muslims with 250,265 (24%), and finally Roman Catholics with 172,787 (17%). History In 1939, a small portion of the Vrbas Banovina with Croat majority (Derventa and Gradačac) in the northeast was detached and made a part of the newly formed Banovina of Croatia. In 1941, the World War II Axis Powers occupied Vrbas Banovina and the province was abolished and attached to the Independent State of Croatia. Following World War II, most of the region became part of the Socialist Republic of Bosnia and Herzegovina within a federal Socialist Yugoslavia. A Dvor district became part of the Socialist Republic of Croatia. Since 1992, the area of the former province has been split between Republika Srpska and Federation of Bosnia and Herzegovina within independent Bosnia and Herzegovina. Bans of Vrbas Banovina Svetislav Milosavljević (1929–1934) Dragoslav Đorđević (1934–1935) Bogoljub Kujundžić (1935–1937) Todor Lazarević (1937–1938) Petar Cvetković (1938–1939) Gojko Ružić (1939–1941) Nikola Stojanović (1941) Cities and towns Banja Luka (capital) Bihać Bosanska Dubica Bosanska Gradiška Bosanska Kostajnica Bosanski Novi Bosanski Petrovac Bosansko Grahovo Cazin Derventa (1939 to the Banovina of Croatia) Doboj Donji Vakuf Drvar Dvor Glamoč Gračanica Gradačac (1939 to the Banovina of Croatia) Jajce Ključ Kotor Varoš Maglaj Modriča (1939 to the Banovina of Croatia) Mrkonjić Grad Prijedor Prnjavor Sanski Most Teslić Tešanj Geographic history of Bosnia and Herzegovina Yugoslav Bosnia and Herzegovina Banovinas of the Kingdom of Yugoslavia 1929 establishments in Yugoslavia 1941 disestablishments in Yugoslavia Former subdivisions of Bosnia and Herzegovina History of Bosanska Krajina