The siege of Szigetvár or the Battle of Szigeth was an Ottoman siege of the fortress of Szigetvár in the Kingdom of Hungary. The fort had blocked Sultan Suleiman's line of advance towards Vienna in 1566. The battle was fought between the defending forces of the Habsburg monarchy under the leadership of Nikola IV Zrinski, the former Ban of Croatia, and the invading Ottoman army under the nominal command of Sultan Suleiman.