Peace Between Suleiman the Magnificent and Ferdinand I

After the Ottoman victory at the Battle of Mohacs in 1526, the Kingdom of Hungary was thrown into crisis with the death of its king. Two rivals claimed the throne: Ferdinand of Habsburg, archduke of Austria and brother of Holy Roman Emperor Charles V, and John Zapolya, a Hungarian noble supported by Sultan Suleiman the Magnificent, whose forces dominated the region.

Years of conflict over Hungary, including Suleiman's failed siege of Vienna in 1529, eventually gave way to negotiated arrangements partitioning the kingdom. Ferdinand held the western and northern strip known as Royal Hungary, while John Zapolya, acting as Suleiman's vassal, ruled central and eastern Hungary including Transylvania. The settlements recognized Ferdinand's portion while preserving Ottoman influence over the rest.

The division of Hungary among Habsburg, Ottoman vassal, and later direct Ottoman rule endured for generations and made the kingdom a long-contested frontier between Christian Europe and the Ottoman Empire. The arrangement confirmed Suleiman's dominance in the region while checking Habsburg expansion. Hungary would remain partitioned in this fashion until the Ottoman retreat near the end of the seventeenth century.