John III - King of Poland

John III was the most well known of the 11 elected kings of the Polish-Lithuanian Commonwealth and one of only four Poles among them. John was a notable military talent, his reign marked by a significant deterioration in the governing capacity of the republic’s legislature, whose members began to abuse their power to veto any proposed legislation without explanation during his reign.

In general, John III was more known for his military than for his governmental or political achievements, but like all Polish monarchs of this period, he was decisively restrained by the commonwealth’s recalcitrant nobles.

Born in Olesko (near L’viv, Ukraine) to a noble family, John III studied at the University of Kraków. As did many Poles of the early modern period, he spent an extended period of travel and study in western Europe.

His maternal grandfather had been a significant military commander, but John III appears to have entered the military first in response to the Chmielnicki Uprising. This uprising was a Ukrainian nationalist revolt that began in 1648 and became a civil war that significantly weakened the commonwealth, allowing Sweden to invade Poland shortly before the war’s conclusion in 1655.

During this period, John III resided briefly at the Ottoman court as Polish envoy, returning to command a Polish regiment that briefly capitulated to the Swedes before reverting to Polish allegiance in 1656. John III took part in the factionalist court politics of the period on the side of the French faction but remained loyal to the Crown during the Lubomirski Rebellion, a revolt against the reforming initiatives of King Jan II Kazimierz Vasa.

Although John III was defeated while defending Vasa, his loyalty during the rebellion led to repeated promotions after 1665, all the way to commander in chief of the Polish army in 1668. This was the same year he married a French noblewoman, with whom he would father seven children.

King John III Sobieski blessing Polish attack on Turks in Vienna 1683
King John III Sobieski blessing Polish attack on Turks in Vienna 1683

John III distinguished himself in repeated border skirmishes with the Ottoman Empire. After a great victory at Chocim in 1673 and the near-simultaneous death of the previous king, John III was elected king and crowned on February 2, 1676.

Because the Swedish invasion had ruined the Polish economy, he moved to foster a tense peace with the Ottoman Empire after 1675. Some historians have suggested that he sought to reunite Prussia with the Polish Crown at this time, but whatever his plans, Polish magnates would not support them.

Over their resistance, he enforced a series of military reforms that included the modernization of the Polish artillery. John III’s most important victory over the Turks came at Vienna in 1683, when he successfully attacked an army about 50 percent larger than his own.

Military struggles continued to influence his later years, although he became ill after 1691, thus enabling the intrigues conducted by the Polish nobles on behalf of various European power at court to flourish in his final years.

This state of affairs made it impossible for the Polish government to conduct business effectively, thus accelerating the coming collapse of the Polish state. John III’s successor, August II of Saxony, became king only with Russian support.