Husaria w natarciu (1918)
Antoni Piotrowski, Public domain, via Wikimedia Commons

On July 14, 1683, Ottoman forces invaded the Holy Roman Empire. Trying to succeed where Suleiman the Magnificent had failed a century earlier, they once again laid siege to Vienna with an army of 150,000 soldiers. The Austrian leader, Holy Roman Emperor Leopold I, had only 11,000 soldiers to defend the city. He appealed to King Louis XIV for aid, but the French House of Bourbon was unwilling to aid the Habsburgs. Saxony, Bavaria, Franconia, Swabia, and a few other Habsburg states in the Holy Roman Empire managed to raise a relief force of 47,000, but not until the siege was well underway.

The siege drew on for nearly two months. Vienna was nearing surrender on September 11, 1683, when King Jan III Sobiewski of Poland-Lithuania arrived with eighteen thousand horsemen (called "Winged Hussars.") The next day, the relief army attacked, breaking the Ottoman lines and lifting the siege.

At the time of the siege, the tsar of Russia was Ivan V, but he was so mentally unstable that his younger half-brother Peter had been elevated to co-ruler, despite being only ten years old. In reality, their older sister Sophia was running the country. In the wake of the siege, Sophia formed an alliance with Poland and Austria, declaring war on the Ottomans. When he was not sailing or playing with his toy soldiers, Peter would have heard of this first serious involvement by Russia in European affairs. When Peter was 17, he banished his sister and took power for himself. He became fascinated with Western Europe. In 1697, he toured England, France, Austria, and the Netherlands "undercover" (he was 6' 8" and didn't fool anyone) with the Russian Grand Embassy. Peter fell in love with Western Europe, and when he returned to Russia, launched a major series of reforms to Westernize the country. His childhood pursuits became realities as he built Russia's first navy in the Black Sea and modernized the army; he implemented the Julian calendar, married members of his family into European royal houses, replaced the boyar duma (council of nobles) with a Senate, and required Russian noblemen to dress in a Western fashion. He even implemented a penalty tax on nobles who refused to shave their beards. Peter dropped the title "tsar" and styled himself "Emperor of Russia." Most significantly, he moved the Russian capital from Moscow to a new city on the Gulf of Finland, five hundred miles closer to Europe, which the emperor christened Saint Petersburg (after Saint Peter, obviously, not himself.)

As Peter was touring Western Europe, the tide had turned against the Ottomans to the point that Turkish sources call this period the "Little Apocalypse." The decisive battle was fought near the Serbian city of Zenta on September 11, 1697. The war formally ended with the Treaty of Karlowitz, in which the Ottomans ceded Hungary and Transylvania to the Habsburgs. This marked the last substantial Ottoman attempt to invade Europe.