Revolutions of 1848 in the Austrian Empire of the Serbs in Austrian Empire was held between 1 and 3 May 1848 in Sremski Karlovci, during which the Serbs proclaimed autonomous Habsburg crownland of Serbian Vojvodina. The war started, leading to clashes as such in Srbobran, where on July 14, 1848, the first siege of the town by Hungarian forces began under Baron Fülöp Berchtold. The army was forced to retreat due to a strong Serbian defense. With war raging on three fronts (against Romanians and Serbs in Banat and Bačka, and Romanians in Transylvania), Hungarian radicals in Pest saw this as an opportunity. Parliament made concessions to
Revolutions of 1848 in the Austrian Empire support Croatian forces under Jelačić. After Vienna was recaptured by imperial forces, General Windischgrätz and 70,000 troops were sent to Hungary to crush the Hungarian revolution and as they advanced the Hungarian government evacuated Pest. However the Austrian army had to retreat after heavy defeats in the Spring Campaign of the Hungarian Army from March to May 1849. Instead of pursuing the Austrian army, the Hungarians stopped to retake the Fort of Buda and prepared defenses. In June 1849 Russian and Austrian troops entered Hungary heavily outnumbering the Hungarian army. Kossuth abdicated on August 11, 1849 in favour of Artúr