Times were not good in the Polish-Lithuanian Commonwealth when Jan Sobieski was elected king in 1674. Nearly fifty years of incessant wars with the Swedes, Cossacks, Tatars, Russians, and Ottomans had drained the treasury and taken its toll on the economy. The Golden Age of Poland was at its end, but one moment of glory still remained to unfold.

Plans in 1658 for the creation of the Principality of Ruthenia, which would then have become a full member of a Polish-Lithuanian-Ruthenian Commonwealth, were shelved after a series of military reversals at the hands of the Cossacks and Russians. The plans were discarded entirely in 1667 after the signing of the Treaty of Andrusovo, whose terms were a clear and ominous indication of the rapid ascendency of the Russian Empire. Despite the standoff results of the Polish-Turkish War of 1672-1676, the Ottoman Empire remained a clear and present danger to Christendom and Europe. These events resulted in the election as king of Jan Sobieski, a proven campaigner and brilliant military strategist, in 1674.

The memorable moment of glory came on 12 September 1683 at the city gates of Vienna. Upon hearing the distressing news of the renewed siege of Vienna by Ottoman forces, King Jan III Sobieski immediately realized the strategic importance of preventing Vienna's fall which would expose all of Europe to Turkish attack and conquest. He raced southward with the Polish Army and joined Holy Roman Emperor Leopold I in the hills above Vienna. Taking command of the combined Austrian, German, and Polish forces, he planned his attack on the Turks for 13 September 1683. But news that the Turks were, at that moment, undermining Vienna's defensive walls and they could be breached at any moment, forced King John Sobieski to change the date and time of his attack to the following morning at 4:00 AM. Thus it was that King John III Sobieski and his combined forces of 81,000 men boldly and desperately charged against the Ottoman foes numbering 140,000. By 5:30 PM the battle was over. Christendom had been saved. The Ottoman Turkish Army was completely routed and fleeing in panic and utter disarray. A humiliated Grand Vizier Merzifonlu Kara Mustafa Pasha fled for his life.

But glory is fleeting. While Jan Sobieski was declared a savior of Christendom and Western Civilization by Europeans and grudgingly "the Lion of Lechistan" by Ottomans, the Polish-Lithuanian Commonwealth was still in decline. The lasting effect of his outstanding victory was that the Ottoman Empire would never again be a threat and was doomed to become "the sick old man of Europe".