The Siege of Belgrade or Battle of Belgrade or Siege of Nándorfehérvár occurred from July 4 to July 22, 1456. After the fall of Constantinople in 1453, the Ottoman sultan Mehmed II was rallying his resources in order to subjugate the Kingdom of Hungary. His immediate objective was the border fort of the town of Belgrade (in old Hungarian Nándorfehérvár). John Hunyadi, a Hungarian nobleman and warlord who had fought many battles against the Ottomans in the previous two decades, prepared the defenses of the fortress.