The wars involving the Ottoman Empire during the reign of John III Sobieski, particularly his campaigns at Khotyn (1673) and Vienna (1683), represent the Commonwealth’s final heroic military engagements amid a century of decline caused by prior wars, uprisings, and external invasions. These campaigns followed the devastating wars with Russia, the Cossack uprisings, and the Swedish Deluge—events that fragmented the Polish-Lithuanian Commonwealth's political structure and drained its military resources.
The Commonwealth's earlier struggles with the Cossacks, including the Khmelnytsky Uprising and the Russo-Polish War (1654–1667), had significantly weakened its grip on Ukraine and emboldened Russia’s territorial ambitions. The Treaty of Andrusovo in 1667, which concluded the war with Russia, left large swathes of eastern Ukraine and Smolensk in Russian hands, reducing the Commonwealth's influence in the region. These losses also created a power vacuum in Ukraine, which invited Ottoman expansion and sparked further instability, as Cossack leaders, including Petro Doroshenko, sought alliances with the Ottoman Empire to regain autonomy.
The Polish–Cossack–Tatar War (1666–1671) further destabilized the Commonwealth in the aftermath of the Treaty of Andrusovo. The war was driven by the ambitions of Cossack leader Petro Doroshenko, who allied with the Crimean Tatars and the Ottoman Empire to consolidate control over right-bank Ukraine. This conflict exposed the Commonwealth’s diminishing capacity to govern its eastern territories effectively, as internal factionalism and magnate rivalries weakened its response to external threats. Although Hetman John Sobieski managed to defeat Tatar incursions at battles such as Podhajce (1667), the war set the stage for future Ottoman advances, culminating in the humiliating Treaty of Buchach (1672). The Polish-Cossack-Tatar War exemplified the growing inability of the Commonwealth to maintain its borders and military cohesion, further complicating its struggles with Russia and exacerbating the long-term decline of the state.
In the midst of this disarray, Sobieski rose to prominence by successfully leading campaigns against Ottoman incursions into the Commonwealth's weakened borderlands. His victory at the Battle of Khotyn (1673) temporarily halted Ottoman advances and provided a brief resurgence in national unity. However, the Commonwealth’s internal factionalism persisted, limiting the scope of Sobieski’s successes. Following the abdication of King John II Casimir and the short reign of Michał Korybut Wiśniowiecki, the Commonwealth's governance remained paralyzed by infighting among the magnates, leaving it vulnerable to Ottoman and Russian maneuvers.
Sobieski’s most famous achievement came in 1683 when he led a coalition army to break the Ottoman siege of Vienna, a campaign that secured the Habsburg Empire and cemented his reputation as the "savior of Christendom." The magnate factions quickly resumed their rivalries, eroding any political unity gained from his military successes. Despite brief moments of national pride, the state was paralyzed by factionalism, with powerful nobles undermining royal authority. Following Sobieski’s death in 1696, the Commonwealth entered a prolonged period of instability. Lacking effective central governance, it became increasingly vulnerable to external pressures from rising powers like Russia, Austria, and Prussia.
Sobieski’s later campaigns, including his involvement in the Great Turkish War (1683–1699), were driven by his alliance with the Holy League—a coalition of European powers formed to counter Ottoman expansion. After the Battle of Vienna (1683), where Sobieski’s leadership ended the Ottoman siege, subsequent campaigns aimed to capitalize on that victory. However, coordination among the Holy League allies proved inadequate. Sobieski's forces embarked on additional offensives, such as the failed Danube campaign in 1686 and an ill-fated expedition into Moldavia in 1691, marking the twilight of the Commonwealth’s military strength. These efforts achieved limited strategic gains, leaving key territories like Kamieniec Podolski in Ottoman hands until the Treaty of Karlowitz in 1699, which concluded the war but highlighted the diminishing influence of the Polish–Lithuanian Commonwealth on the European stage.