The fifty-nine-day siege ended with the arrival of the imperial and Polish relief army under the command of Charles V, duke of Lorraine, and King John III Sobieski (ruled 1674 –1696) on 11 September 1683. Count Ernst R üdiger von Starhemberg ably directed the 15,000-strong defense forces, but by early September heavy Ottoman bombardment and mining opened numerous breaches in the walls, and the defenders were running short of supplies. With the auxiliary troops of Crimean, Walachian, Moldavian, and Transylvanian vassals, the army that reached the outskirts of Vienna by early July numbered some 150,000 men, although only 40,000 were central troops of the standing army and although, as in 1529, the Ottomans lacked heavy siege artillery. The recent revival of Ottoman military fortunes, the renewed Franco-Habsburg rivalry, and, more importantly, the weakness the Habsburgs had shown in Hungary against Imre Th ök öly's Kuruc insurrection (1681 –1683), persuaded Kara Mustafa Pa şa, the ambitious grand vizier (1676 –1683), that the time had come to conquer Vienna. The 1660s saw new Ottoman conquests in Hungary (16), Crete (1669), and Poland-Lithuania (16) under the able leadership of the K öpr ül ü grand viziers. In 1683 Vienna was besieged for the second time by the Ottomans, who by 1541 had conquered central Hungary, bringing the frontier dangerously close to the Austrian capital. After another failed attempt in 1532, when the small Hungarian castle of K üszeg (G üns) stopped Suleiman's army, the sultan and Ferdinand accepted the status quo in Hungary. With winter approaching, the Ottomans raised the siege. The defenders discovered or disarmed most of the Ottoman mines, and when some mines did succeed in opening significantly large holes, the attackers were repulsed by pikemen and harquebusiers. The Ottoman bombardment was not effective, for the attackers had had to leave their siege artillery in Bulgaria and Hungary owing to unusually rainy weather and muddy roads. The siege lasted for some two weeks (27 September –15 October 1529). Vienna was defended by some 18,000 to 25,000 soldiers under the able leadership of Niklas Graf zu Salm and Wilhelm Freiherr von Roggendorf, who had ordered the city's medieval and obsolete defenses substantially strengthened. Suleiman, however, wanted the resolve the Habsburg-Ottoman rivalry in Central Europe by conquering Vienna, the capital of the Habsburgs' Danubian Monarchy. The Ottoman army of 80,000 to 100,000 men retook Buda, Hungary's capital, from the Habsburgs in September 1529 and gave it back to their ally J ános. After Suleiman's prot ég é, J ános Szapolyai (ruled 1526 –1540), was ousted from Hungary by his rival, Ferdinand I of Habsburg, also elected king of Hungary (1526 –1564), Suleiman was eager to redress the unintended consequences of his victory at Moh ács. When, at the battle of Moh ács in 1526, the troops of Sultan Suleiman I (ruled 1520 –1566) wiped out the Hungarian army and killed King Louis II, they cleared the way to the Hungarian throne for their main rival, the Habsburgs.

The city of Vienna was the object of two unsuccessful sieges by Ottoman forces during the early modern period.

Siege of vienna opening bombardment