|Campaign of Ferdinand I|
|Part of the Ottoman–Habsburg wars|
Holy Roman Empire
Kingdom of Bohemia
Kingdom of Croatia
Ferdinand's Hungarian kingdom
John Zapolya's Hungarian kingdom
|Commanders and leaders|
Ferdinand I, Holy Roman Emperor|
Jovan Nenad †
Peter IV Rareș
Suleiman the Magnificent
|Casualties and losses|
The Hungarian campaign of 1527–1528 was launched by Ferdinand I, Archduke of Austria and King of Hungary and Bohemia against the Ottoman Turks. Following the Battle of Mohács, the Ottomans were forced to withdraw as events elsewhere in their now massive Empire required the Sultan's attention. Seizing upon their absence, Ferdinand I attempted to enforce his claim as King of Hungary. In 1527 he drove back the Ottoman vassal John Zápolya and captured Buda, Győr, Komárom, Esztergom, and Székesfehérvár by 1528. Meanwhile, the Ottoman Sultan, Suleiman the Magnificent, took no action at this stage despite the pleas of his vassal.
For the Habsburgs, the victory here would be a very disappointing one. On 10 May 1529, Suleiman the Magnificent launched his own counter-attack negating all of Ferdinand's gains. Of greater disappointment was the fact that many of the recently captured forts surrendered without resistance, greatly speeding up the advance. As a result, Suleiman was able to reach and besiege Vienna.