Chapter 129: Triumph of the Holy League
The Franco-Dutch War had coincided with an Ottoman invasion of the Austrian Habsburg lands which began what would later be known as the Great Turkish War. Capturing Vienna had long been an aspiration of the Sublime Porte since the bygone days of Suleiman the Magnificent, and grand vizier Kara Mustafa Pasha was eager to accomplish this enticing goal. Although initially hesitant, Mehmed IV was eventually persuaded to take up his grand vizier’s grandiose proposal in the face of Habsburg incursions that had begun after Upper Hungary elected Imre Thokoly as their new prince and broke off from the Habsburg fold into Constantinople’s. The ongoing Franco-Dutch War provided further encouragement for a full-scale campaign against Vienna as it preoccupied the attention of potential allies of the Holy Roman Emperor in western Europe. Thus, in April 1683, an enormous Ottoman force of 150,000 men led by Mustafa Pasha himself began marching from Edirne towards Vienna. Along the way, they would be joined by the armies of Transylvanian prince Michael Apafi and Imre Thokoly.
Portrait of Kara Mustafa Pasha
The siege of Vienna began on July 14, the city having been evacuated by Emperor Leopold who had fled to Passau to prepare a proper counter-response. After digging trenches to protect themselves from enemy fire, the Turks dug mining tunnels which would be filled with black powder intended to explode under Vienna’s walls and destroy them. However, the defenders were able to reinforce the outer palisade by knocking tree trunks into the ground, prolonging the Ottoman’s efforts by 3 weeks. The Viennese advantage in artillery also dissuaded any full-frontal assaults upon the city. Nevertheless, Mustafa Pasha was able to cut off the food supply and the defenders were on the verge of capitulation when news of a Polish relief army led by the king John Sobieski himself defeating Imre Thokoly at Bisamberg [1], just 5 km northwest of Vienna, reached the besieged city and gave the populace renewed hope. It would be this relief army of 18,000 that heralded the beginning of the anti-Ottoman response, with Lithuanians, Cossacks, and Imperials on their way as well.
Mustafa Pasha attempted to respond to this impending threat by assigning Kara Mehmed of Diyarbakir to take a contingent of 24,000 to track down and confront Sobieski before he could coalesce with other Christian reinforcements. Sobieski, however, cleverly avoided open battle, instead deploying cavalry led by his brother Marek to repeatedly harass and wear down Kara Mehmed’s detachment. Only on September 7th did the king plan a joint assault with the Germano-Imperial reinforcements under Prince Georg Friedrich of Waldeck and in the ensuing battle flanked and defeated the Ottoman detachment, even killing Kara Mehmed in the process. After this victory, the now-gathered anti-Ottoman forces quickly organized, with John Sobieski as the commander-in-chief and George Friedrich, Saxon elector John George III, and Marek Sobieski as deputy commanders. This army, numbering 70,000+ now descended upon the besiegers. Forced to pause his siege of Vienna, Kara Mustafa Pasha ordered counterattacks upon the approaching Christian forces with mixed results as the Turks and their allies were already exhausted and demoralized from the grueling siege and news of the initial Christian victory. The iconic moment of the battle was a cavalry charge led by John Sobieski and 3,000 winged hussars, the largest in recorded history, that descended from the Kahlenberg hilltop and finally broke the Ottomans’ ranks, forcing a messy retreat back into their territories. They had lost around 40,000 men and Vienna proved to be such a massive defeat that the grand vizier would be executed by Mehmed IV upon his humiliating return.
Battle of Vienna, painted by Gonzales Franciscus Casteels
Upon their victory, the participating powers would quickly form a Holy League to undermine the Sublime Porte’s ability to organize large-scale invasions into Europe. The Commonwealth and much of the Holy Roman Empire would be joined by the Venetian Republic and later the Russian Tsardom, uniting an unprecedented amount of political and military power against the Ottomans. The Great Turkish War, as the subsequent conflict would be known as, branched out into several regional theaters from the great victory at Vienna. The main theater would be the Hungarian one which began even before the Holy League had formally been established. Initially set back by the death of Marek Sobieski to dysentery while on campaign, League forces under the leadership of commanders like prince Georg Friedrich and Louis William, margrave of Baden-Baden, were able to rapidly advance upon Buda and had recaptured the historic capital of Hungary by 1686. The Holy League would receive another boost that same year with the conclusion of the Franco-Dutch War, freeing up reserves previously stationed in case of a potential intervention. These successes would reach their peak with the 2nd Battle of Mohacs in 1687, which saw a League victory so great it triggered a mutiny within the Ottoman armed forces that ultimately saw the deposition of padishah Mehmed IV in favor of his younger brother Suleiman. Things went even more smoothly against Transylvania, where nobles still angry at the Turks for displacing the Rakoczis from prominence in 1677 allied with the League against Michael Apafi. The subsequent civil war within the principality would result in a Habsburg-Rakoczi victory and the teenage Francis Rakoczi was promised the princely title once he was of age.
While the Habsburgs and their Imperial forces romped in Hungary, the Commonwealth pressed Constantinople in the lands of its Moldavian and Crimean vassals. At first, the anti-Ottoman Stefan Petriceicu seized power in Moldavia after its prince, the pro-Ottoman George Ducas, was captured on the Viennese battlefield and flipped his realm’s allegiances towards the Commonwealth. However, the Turks acted quickly, replacing him with Dumitrascu Cantacuzino within months. This prompted a campaign by John Sobieski into Moldavia in 1686 and although he found initial success, his army quickly began to be bogged down in siege after siege as the Turks refused to give battle and chose instead to harass and wear down the Christian forces. It didn’t help that much of the Commonwealth’s nearby Cossack military strength was directed towards the Crimean Tatars, who proved to be resilient even with Russian participation in the war in 1686 onwards. Lithuanian reinforcements under the command of Lithuanian Crown Hetman Kazimierz Jan Sapieha would tip the balance in favor of the anti-Ottoman coalition within a few years, however, and in 1689 Sobieski successfully deposed prince Constantin Cantemir [2] after taking the capital of Iasu, replacing him with his more pro-Commonwealth son Antioh.
From here, John Sobieski ordered Sapieha and the king’s nephew Jakub [3], son of his late older brother, to hold down Moldavia while the king turned his attention to the Crimean front which was at a stalemate as the outnumbered Tatars utilized scorched earth retreats and raids, managing to completely halt the Russian advance and devastate parts of Yedisan and Zaporhizia. By 1689, Russia was undergoing its own domestic strife as the teenage co-tsar Peter I overthrew his half-sister and controlling regent Sophia, leaving a opening for the Khanate that Sobieski and Cossack leader Tymofiy Khmelnytsky could ill-afford to overlook. The Polish-Lithuanian king, hoping to replicate another Vienna-esque victory that could cripple the Crimean war effort, marched upon Perekop, a choke point between the Crimean peninsula and the mainland steppe, at the head of an army of 40,000 Poles and Cossacks. Along the way, a sizable Tatar army led by khan Selim I Giray attempted to intercept Sobieski, only to be soundly defeated. A months-long siege of Perekop and occupation of its surroundings followed, ultimately resulting in its capture in November 1691. Shortly after this, however, the aging king returned to Warsaw and handed command over to Polish Crown Hetman Stanislaw Jan Jablonowski, and the rest of the war saw only marginal gains for the Commonwealth.
Battle Against Tatars by Jozef Brandt
The Holy League would even be able to advance into the Balkans. In Serbia, supportive rebels formed the Serbian Militia and allied with the League, enabling the capture of Belgrade in 1688 and League advances as far south as Skopje. However, a counteroffensive led by grand vizier Kopruluzade Fazil Mustafa Pasha reversed nearly all of these gains and even caused a mass migration of ethnic Serbs northwards through his army’s brutal and persecutive behavior. The grand vizier’s advance would only be halted at the Battle of Slankamen in 1691, which confirmed Habsburg gains in Hungary, Croatia, and Transylvania. Another Ottoman counteroffensive would be organized, this time against Moldavia in order to drive out the Commonwealth and dethrone Antioh Cantemir. The Turkish and League armies would clash in 1691 at the Battle of Finta and here, Sapieha’s brilliant generalship and the fighting spirit of the Moldavian contingent led to a stunning victory for the Commonwealth-Moldavian forces. It was with this battle that Moldavia’s break with the Sublime Porte was confirmed for good.
Further south, Venice invaded Greece and Dalmatia and conducted naval operations in the Aegean Sea from their strategic position on Crete. Although the Republic’s fleet and trade power had been in decline throughout the 17th century, they were still able to overpower the Sublime Porte on the seas, whose own naval presence had been neglected and further resources diverted towards the more critical land battles against the Habsburgs, the Commonwealth, and their allies. Bolstered by aid from Pope Innocent XI and other Italian supporters, Venetian commander and future doge Francesco Morosini led the Republic to victory and had conquered the Ionian islands, the Negropont, Dalmatia, and southern and central Greece. Here too would the Ottomans attempt to launch a counteroffensive though their efforts would only succeed in calcifying the frontlines. A Turkish fleet under the command of Mezzo Morto Pasha would even attempt an amphibious landing and conquest of Crete in 1691 although this expedition would ultimately fail.
The Holy League’s string of victories were so devastating for the Sublime Porte that the latter entered peace negotiations in 1692. On November 16th, 1692, the Treaty of Karlowitz [4] would be signed which laid out the Holy League’s gains. The old Hungarian lands as well as Croatia and Transylvania were ceded to the Habsburg realm, with the latter now a semi-autonomous region of the Kingdom of Hungary. Further into the Balkans, Dalmatia, the Ionian islands, the Morea, and the sanjak of Egriboz [5] would be ceded to Venice. Meanwhile, Moldavia was formally recognized as a vassal of Poland-Lithuania while the Commonwealth itself made minor territorial gains at the expense of the Crimean Khanate. Notably, as Russian involvement in the Great Turkish War had ended after 1689 they were not part of the negotiations and thus did not acquire new lands from the Crimean Tatars. This would later be a point of contention between Moscow, Constantinople, and Warsaw. For now, though, Europe celebrated the unprecedented rollback of Ottoman power and influence in Europe while the French were despondent over the defeat of one of their key allies.
[1]: IOTL, Charles V of Lorraine defeats Thokoly here but ITTL Lorraine is involved in the Franco-Dutch War so the Commonwealth, which is stronger ITTL, fights this battle here instead.
[2]: Constantin Cantemir drove Dumitrascu Cantacuzino out of Moldavia in 1685 IOTL and ITTL.
[3]: Marek Sobieski’s firstborn son
[4]: The Holy League is able to end the war 7 years earlier because the Nine Years’ War is butterflied away ITTL and are also able to make greater territorial gains as a result of not having to divert manpower and resources towards another European conflict.
[5]: The Negropont and the Attican region of Greece