Eastern Hungarian Kingdom

The Eastern Hungarian Kingdom is a modern term used to describe the realm of John Zápolya and his son John Sigismund Zápolya, who challenged the House of Habsburg's claims to rule the Kingdom of Hungary from 1526 to 1570. Founded on November 11, 1526, and dissolved on August 16, 1570, this kingdom encompassed an eastern part of Hungary, while Habsburg kings ruled the west. The Ottoman Empire supported the Eastern Hungarian Kingdom, preventing the Habsburgs from uniting all of Hungary under their rule. Its capitals included Buda, Gyulafehérvár, and Kolozsvár. The Eastern Hungarian Kingdom is considered the predecessor of the Principality of Transylvania.