First Migration
In 1690, Emperor Leopold I allowed the refugees gathered on the banks of the Sava and Danube in Belgrade to cross the rivers (and to settle in Habsburg Monarchy), he recognized Patriarch Arsenije III Čarnojević as their spiritual leader. The Emperor had recognized the Patriarch as deputy-voivode (civil leader of the migrants), which over time developed into the etymology of the northern Serbian province of Vojvodina (this origin of the name of Vojvodina is related to the fact that patriarch Čarnojević and subsequent religious leaders of Serbs in the Habsburg Monarchy had jurisdiction over all Serbs in the Habsburg Monarchy, including Serbs of Vojvodina, and that Serbs of Vojvodina accepted the idea of a separate Serbian voivodeship in this area, which they managed to create in 1848).
In 1694, Leopold I, Holy Roman Emperor appointed Arsenije III Čarnojević as the head of the newly established Orthodox Church in the Monarchy. The patriarchal right of succession was secured by the May Assembly of the Serbian people in Karlovci in 1848, following the proclamation of Serbian Vojvodina during the Serbian revolution in Habsburg lands 1848-49. Serbs received privileges from the Emperor, which guaranteed them national and religious singularity, as well as a corpus of rights and freedoms in the Habsburg Monarchy.
Most of the Serbs from this migration settled in the territory of present-day Hungary, while smaller part of them settled in the territory of present-day Croatia and present-day north-western Vojvodina (the rest of Vojvodina was still under Ottoman administration). This, however, did not result in a significant increase of existing Serb population in the territory of present-day Vojvodina. Serbs (together with Muslims) were recorded as a dominant population in Vojvodina long before the migration, i.e. in the time of Ottoman administration (16th-17th century).
Read more about this topic: Great Serb Migrations