Jan Sobieski was an excellent king for the period during which he was elected. His father wanted to educate both his sons well and first sent them to study at the University of Cracow, in the Faculty of Philosophy. Later, he sent both of them abroad, where they could complete their education. Subsequently, the future king had the opportunity to learn the art of war on all the fronts where Polish armies fought. He took part in the Battle of Beresteczko in 1651 (in the Ukrainian rebellion led by Hetman Bohdan Chmielnicki), during the Polish-Swedish war (1655-1660) and in the Battle of Warsaw, where he commanded Tartar units fighting on the Polish side against the Swedes. Next he fought against the Transylvanians, Russians, Cossacks and Tartars, as well as against rebels who, led by Prince Lubomirski, rose against King Michał Korybut Wiśniowiecki in 1666. His special success was the defeat of the Turkish army at Chocim in 1673. It was this victory that helped to get him elected king of Poland a year later.
The experience he gained on the battlefields came to fruition in an event which was significant not only for the history of Poland. By the late 17th century the Turks were attempting to penetrate deeper and deeper into the heart of Europe, threatening Vienna. Realising that should Vienna fall, Poland would find herself in a very difficult position, in 1683 Sobieski set off to relieve the besieged city. On 12 September 1683 Polish hussars (heavy cavalry with characteristic plumage on their backs) under Sobieski's command gained a victory, thus definitively stopping the Turks in one of the greatest and most significant battles in Europe at the time. Nowadays that march to Vienna is referred to as the Relief of Vienna. Sobieski wrote numerous letters to his French wife, Queen Marie Casimire d'Arquien ('Marysieńka'), describing the battle which decided the fate of Europe. His letters make up a fascinating chapter in Old Polish epistolography.
Sobieski's great love for his wife also had political consequences, as it tied him to the French court. Thanks to that, he understood the need for domestic reform and a change in Poland's foreign policy. Thus he wanted to strengthen Poland's position on the Baltic coast by taking East Prussia, and to retrieve Polish Silesia from the Habsburgs. In his home policy, by trying to make Poland a hereditary monarchy and to abolish the principle of liberum veto (viz. statutes were passed in parliament only by a unanimous vote), he attempted to enhance royal prerogative, which had become too dependent on the magnates. However, these reforms were not implemented due to the opposition by part of the noble estate, which had become too accustomed to the enjoyment of significant privileges.
Sobieski was not only a great military leader, but also an excellent politician. He died on 18 June 1696, leaving a memory of the great glory of Polish military prowess.