Banovina of Croatia, 1939
Soon after the Kingdom of Serbs, Croats and Slovenes formed, it became clear that most powers were in the hands of the ethnic Serb population. In 1929 internal borders were redrawn, forming nine “banovinas” (administrative subdivisions), six with Serb majorities. In 1939, after years of actions by Croatian regionalists, the central government consented to merge two of the nine banovinas, Sava in the north and east and Littoral along the coast, into one: the Banovina of Croatia. They adopted their flag, a red-white-blue horizontal tricolour with the checkerboard shield on the central stripe.