Ottoman Pressure on the Serbian Despotate

Timeline

1. 1411–1413Belgrade · SerbiaMehmed I reunified the Ottoman Empire around 1413 and immediately demanded stronger tribute and military obligations from Balkan vassals. Stefan Lazarević had to balance submission to the Ottomans with preserving Serbian autonomy, and Belgrade became his key fortress against Ottoman advances from the south.
2. 1414–1417Southern Serbian frontier · SerbiaAfter consolidating rule, the Ottomans repeatedly levied Serbian troops for campaigns against Hungary and local rebels. Stefan Lazarević was forced to send forces, tribute and military burdens increased, and discontent with the pro-Ottoman policy simmered within the Despotate.
3. 1417–1419Srem · VojvodinaDrawing on his alliance with Hungary and the fortified defenses of Belgrade, Stefan Lazarević still preserved the Serbian Despotate's de facto independence in the later 1410s. Yet Ottoman pressure kept mounting, and the Despotate's room for maneuver in Balkan politics steadily narrowed.