In August of 1526, Sultan Suleiman II (also known colloquially as Suleiman the Lawgiver or Suleiman the Magnificent) smashed the forces of King Lajos II of Hungary at the Battle of Mohacs. Following the conquest and following subjugation of Hungary, Suleiman turned his attention to Austria, where Archduke Ferdinand eyed Suleiman's advances, coming to quickly realize their importance to the survival of his own kingdom, not to mention Christian Europe (although to which his sympathies lay is an unsettled question).
Three years following his conquest of Hungary, in the spring of 1529, Suleiman's armies began a general mobilization in Ottoman Bulgaria, mustering a host of around (or possibly surpassing) 325,000 men, 90,000 camels, and 500 artillery. Included among them was a force of at least 20,000 of the elite janissary corps, and a small force of Christian Hungarians fighting for their new Turkish rulers. With Suleiman acting as commander-in-chief and his grand vizier, a Greek slave known only as "Ibrahim" acting as seraskier (a commander equivalent to a Western field marshal), the army set out soon after for Vienna.
The spring rains characteristic to that part of central Europe were particularly fierce that year, making many of the major roads in the area - including those leading to Vienna - a soggy, barely-passable mess. Thousands of camels were lost when they broke their legs and had to be slaughtered, and about two hundred of the heaviest field guns were turned back due to the roads. Acting against the advice of seraskier Ibrahim, however, Suleiman pressed on, saying, "It is beneath my dignity to allow the weather to interfere with my plans." Therefore the force pressed on, intending to rely on the disciplined ranks of Balkan miners to subvert the walls and setting the stage for the macabre combat ahead.
The populace of the city reacted with terror when news reached them of the advancing Ottoman force. Stories of their inexorable approach, especially the tales of the janissaries' murderous brutality (a notable example being the massacre of the surrendering German garrison and, subsequently, the populace of the town of Pest) infused the city with first a sense of fear and then a resigned will to fight to the death that would serve it well during the siege to come. Ferdinand I, however, had none of this will - he fled to the relative safety of Hapsburg Bohemia following the rejection of pleas to his brother, Charles V, Holy Roman Emperor, for help. His designated commander, a Duke Frederick, then gave operational command of the defence to a 70 year-old German mercenary named Nicholas, Graf von Salm.
He arrived with 1,000 German Landsknechte, formidable mercenary pikemen, and another 700 Spanish musketmen. Taking charge of the garrison of 23,000 infantry, 2,000 cavalry, and 75 cannon, he moved desperately to reinforce the city's 300 year-old walls, pierced by four gates and surrounding St. Stephen's Cathedral, which he would make his headquarters. He ordered the digging of fireproof magazines and erected earthen bastions for defenders to mount in case the wall (reinforced by paving stones) should be breached. Flammable shingles were torn from the roofs, and the four gateways were heavily reinforced.
In a move to preserve what food the city had stored in the event of siege, Salm ordered about 4,000 women, children, and elderly men out of the city via an escorted column. However, by this time lower Austria had been inundated by the Ottomans' advance parties, and most of the group was slaughtered 'en masse' at Traismauer, with particular cruelty being shown to some who were impaled on stakes (although some young women were left alive to be sold as slaves). Resistance within the city - which now saw itself as the final bulwark for Christianity - was uplifted and entrenched, even as Austria burned around the helpless defenders. By late September - two months tardy - the Ottoman host had arrived.
By the time they arrived, the Turkish army was far more formidable on paper than it was in reality. From the drenching country rains barely 20,000 of the camels remained as many of the men, too, took ill with fever or chills. Even of those able to fight, a third were light cavalry (sipahis), next to useless in siege warfare. Even so, the sight of tents as far as they could see struck renewed fear into the besieged city. It is possible they might have capitulated if not for Von Salm's steely resolve, and when Ottoman emissaries threatened to raze the city if it did not surrender, he returned them with honor but without reply.
The next day, the remaining 300 cannons opened fire simultaneously, the gunners having successfully made a superhuman effort to keep their powder and shot dry. The results were predictably negligible, however, as the guns were designed for use against men, not walls. Bowmen, too, fired their arrows with little effect. Salm reportedly remarked as balls crashed into the spires of St. Stephen's, "These pebbles are like the little pills my medico bids me swallow."
His response was a dramatic raid by a small unit of a hundred cavalry under Eck von Reischach that took the Turks by surprise and managed to kill two gun crews before fleeing back behind the walls. This had a great effect on the morale of both sides but did little to effect the battle. For several days, the bombardment continued uselessly with no signs of assault.
On 1 October, however, a miner of Christian parentage that escaped into the city reported that the real purpose of the bombardment was to mask tunnelling efforts beneath the city. The Carinthian Gate, one of the city's four entrances, was the apparent target of this new assault, with the intent being to blow up the towers and then attack with assault troops. Salm, an expert in tunnelling, quickly took ingenious steps against the efforts, including placing buckets of water and dried peas near the cellar walls of homes adjacent to the gate. When they shook, an alarm was sounded and counter-miners commenced digging "like moles". What they discovered were six different tunnels, quickly moving through the Earth and towards the helpless bastions.
The Austrians dug until they struck the enemy tunnels, some of which were deserted, with powder kegs ready to be lit (these were carried off as booty) and some which were still occupied by miners and immediately became the site of bizarre combat. Guns were unusable due to the proximity of the kegs, so the men fought with whatever tools or body parts they could muster, each blow finding a target and countless fighting dying like, in the words of one witness, "devils from the nether pit of hell", returning above approaching insanity and covered with blood. As the battle continued, new weapons were devised for the underground war, including Turkish cavalry maces and Austrian sharpened spades as the fighting below ground grew even more fierce. At one point, a powerkeg prematurely exploded, killing dozens on both sides. The total death toll from this mini-war is still unclear, but it was here originated the term that would come to define the battle, the Siege of the Moles.
The majority of the mines were discovered before any damage could be done, but constant digging exhausted Viennese capabilities and on 5 October two mines exploded beneath the Salt Gate, leaving room enough for a company of soldiers to break through. Janissaries immediately stormed the breach but were met by twelve-foot pikes and halberds, repulsing them with heavy losses. Within hours the breaches were refilled.
The night after, the Austrians replied with a new form of deadly assault. Dozens or possibly hundreds of fanatics wearing cloaks of black and armed with homemade bombs - quite possibly one of the first appearances of the Molotov cocktail - exited the city in silence and strode into the Ottoman camps, tossing their bombs into tents before making their escape. As many as 2,000 Turks died unawares, sleeping.
The fighting continued unabated. Some days later a mine finally brought down the two towers of the Carinthian Gate, bringing them down and opening it to assault, but the advance was held back by Spanish harquebusiers, German pikemen and Bohemian two-handed swordsmen with a heap of 1200 janissary dead left behind at the end.
Suleiman could now see that his mining was becoming at best dilatory and at worst counter-productive, as it went on day after day with no end in sight. Meanwhile, on 11 October, more rain fell and thousands more camels died while the Viennese began mounting cannons on rooftops, including so-called "royals" with greater range than any Turkish gun that raked the Ottoman camps with fire nonstop. As if that weren't enough, the Turks had devastated the surrounding land so food began to grow scarce and the weather sickened even more of his army. Finally, on 11 October, Suleiman held a council of war that decided upon one, final assault.
On 14 October, the attack began, with seraskier Ibrahim leading the charge personally. The drives were aimed at the ruined Carinthian Gate and the bastion nicknamed The Berg. The assault was led by bashi-bazouks, militia intended to tire the Austrians with sheer crush of humanity, to be followed by janissaries, who for the first time were offered a bounty of silver where heretofore only fervor had sufficed. Suleiman ordered that regardless of losses the attack be launched three times - he would either win or suffer dearly in the attempt.
One mine failed to blow, but the other succeeded and with screaming battle cries the Turks broke through the breaches only to be faced again with palisades and long pikes. The baski-bazouks charged twice and fell back twice as they were cut down again and again by pike and musket. The janissaries too struck with murderous fervor and were too beaten back, with piles of bodies collecting where they tried and failed. Hand bombs rained upon them as grapeshot from cannons on the Berg cut through their ranks. Salm had descended from St. Stephen's to assume personal command of the battle, almost immediately being hit, a wound from which he would soon after die.
Finally, without being ordered, the janissaries fell back despite Ibrahim's efforts to whip them into another charge. They immediately swarmed back to the camp and struck their tents, unpursued. The siege was over.
The Turks quickly packed their campsites that night, tossing captured Austrians into the fire as they did. Pandemonium reigned throughout, however, and many managed to escape to the walls of the city, where ladders were lowered for them, the Viennese still not believing it was all over. The next day, as the Ottomans disappeared, snow began to fall on Vienna as the defenders cautiously crept out of their fortress, the weather that had saved it once more displaying itself.
Ottoman casualties were thought to be in the neighborhood of 20,000 - 25,000 men, many more than the garrison's, although most of Austria south of Vienna was depopulated, piles of skulls all that remained of its villages.
In Vienna, the defenders examined each man let into the city following the siege for circumcision, believing the Turks had smuggled in spies and hanging immediately those that failed the test. In the Turkish camps, they found bags filled with coffee beans - their first appearance in Europe - which were used by the Turks as a stimulant, alcohol being forbidden. The stuff caught on, and coffee was soon a European sensation.
Overall the invasion and subsequent siege required a ghastly price from both sides, with tens of thousands of soldiers and civilians dead and thousands more sold into slavery. Practically, it marked the end of the Ottoman advance into Europe and the beginning of their decline from dominant power in the Renaissance world. While they would remain strong for many years after - even mounting another siege, resulting in the Battle of Vienna a hundred years later, they would never again reach their prior heights of power.The Ottomans
The Austrians
Opening
The Moles
Endgame
Aftermath