Yosif Rayachich was not a "voyvoda" but a 19th century Bishop of Karlovtsi, and later a Serbian patriarch. His sad contribution to the Serbs in Voyvodina was to change the character of their 1848 revolutionary uprising and support the Austrian court against Hungarians. The "reward" his loyalist work brought to the Serbs in Voyvodina was that the Serb status of the province was abolished by Emperor Franz Joseph of Austria and turned into an administrative region.
Some of these Serbs fled from the Turkish occupation and ethnic cleansing of Kosovo (see Arsenije III Charnoyevitch)
Yes that was at the end of the 17th century. They fled Kosovo because they rebelled against the Turks during the Austro-Turkish war, after the Austrians were routed by the Turks leaving the Serbs behind to pay the price...starting with the destruction of the Patriarchy of Pech and a decimation of the Serb pipulation. Had it not been for Montenegrins, the Serbian Orthodox Church would have been extinsguished, so we are forever to be mindful of that.
The Great Resettlement of Serbs was therefore a self-inflicted, but understandable misery, fueled by their desire to be free for which we can never fault them. But they can be faulted for their lack of common sense. Despite the fact that the Serbs have always ben let down by the great "allies" they chose in the past (and present), they nevertheless trusted Austrians to somehow protect their miserable lives after Austria was defeated. Yet, right after they were abandoned they went right back to them -- settling in the Banat, Bachka, Srem and Baranya regions which were scarcely populated, but nevertheless populated by non-Serbs. Krayina is diferent: it was not populated by Croatians, and Krayina was created a few centuries earlier. So, I stand by what I wrote in my reply to Tamodaleko and you. We need to come to grips with our own past and reality.