Serbs had been rewarded for their participation in an army that had quelled a Magyar rebellion in 1848–49 by the creation of a semi-autonomous Vojvodina (“Duchy”).
This includes part of the former Banat of Temesvár, most of Backa (between the Danube and Tisa rivers), and a small part of Baranja (between the Danube and Drava rivers)—all of which had long been integral parts of the Hungarian kingdom.
Even during the time of Turkish occupation, the region had begun to receive Serb migrants, and their numbers had increased significantly after the Ottomans were forced back across the Danube.
In addition, Magyar nobles had introduced peasant settlers from the Rhineland and Upper Austria, adding further to the ethnic mix.
The Ausgleich, or Compromise, of 1867, establishing the Dual Monarchy of Austria-Hungary, eradicates the autonomous status of the Vojvodina and exposes its Serbs to the full force of Magyar attempts at assimilation.