[1] The siege was part of a struggle between the Habsburgs and the Ottomans following the death of the ruler of Hungary, John Zápolya, on 20 July 1540.

[3] Suleiman had captured the cities of Buda and Pest in 1541, giving him a powerful control over central Hungary.

[5][6][7] Meanwhile, in the Mediterranean Sea, Suleiman had sent his fleet admiral Hayreddin Barbarossa to cooperate with the French, leading to the siege of Nice.

[8] However, Suleiman refrained from moving further on to Vienna this time, apparently because he had no news of the campaigns of his French allies in western Europe and in the Mediterranean.

[9] After the successful Ottoman campaign, a first truce of one year was signed with Charles V in 1545, through the intermediary of Francis I of France.