Sobieski family Polish Rroyalty_Sobieski, therefore, though always an admirer of France, shifted away from the French alliance and concluded a treaty with the Holy Roman emperor Leopold I against the Turks (April 1, 1683). By the terms of the treaty, each ally had to support the other with all his might if the other’s capital were to be besieged. Thus, when a great Turkish army approached Vienna late in the summer of 1683, Sobieski himself rushed there with about 25,000 men. Because he had the highest rank of all military leaders gathered to relieve Vienna, he took command of the entire relief force (about 75,000 men) and achieved a brilliant victory over the Turks at the Kahlenberg (September 12, 1683), in one of the decisive battles of European history.

In the campaign that followed in Hungary (in the autumn of 1683), however, Sobieski was less successful, and his relations with the emperor Leopold deteriorated because of differences in temperament and conflicting political plans. Sobieski’s idea was to liberate Moldavia and Walachia (present-day Romania) from Ottoman rule and to expand Poland’s influence to the shores of the Black Sea. But his advances into Moldavia, undertaken between 1684 and 1691, were mostly failures, and during the last one he was even in danger of being captured. Despite his previous victories, he was thus not able to achieve his objective. Only in 1699, three years after his death, were the territories that had been lost in 1672 recovered.
In the last years of his life, from 1691 until his death in 1696, Sobieski was often seriously ill and had to face quarrels with the nobles and within his own family. His eldest son, James, was bitterly opposed to the queen and the younger princes. All of Sobieski’s sons were interested in succeeding to the throne and tried to obtain help, either from the emperor or from France. The marriage of Sobieski’s daughter Kunegunda to Maximilian II Emanuel, elector of Bavaria (1694), was the only bright spot in these rather gloomy years.
Although the second half of the reign was much less brilliant than the first, the personal wealth of the royal couple continued to grow because they knew how to obtain money in exchange for offices and favour. Thus, the king left a considerable fortune when he died.
Sobieski also spent large sums on his residences in Żółkiew and Jaworów and especially on the palace of Wilanów near Warsaw, a fine example of Baroque architecture. He was also a patron of poets and painters. Of all the Polish rulers of the 17th century, he was the best educated and took the greatest interest in literature and cultural life.
The struggle against Ottoman power in Europe was the keystone of Sobieski’s foreign policy, with which all other foreign relations were closely connected. When the Russians, traditionally Poland’s enemies, showed willingness to join the league against the Turks, Sobieski concluded with them the “Eternal” Peace of 1686 (the Grzymułtowski Peace). In this treaty, Kiev, which had been under temporary Russian rule since 1667, was permanently ceded by Poland. But despite all the failures and disappointments he experienced after 1683, Sobieski was able to deliver southeastern Poland from the threat of Ottoman and Tatar attack.
In domestic policy Sobieski was least successful. All his endeavours to strengthen the position of the crown and stabilize the army failed completely, and his own sons opposed him. The nobles showed little interest in defending the country after the great victory of 1683 had been won, and the Lithuanian magnates fought each other rather than the Turks. Thus, John Sobieski, although a brilliant general and organizer, was unable to prevent rebellion in his family and the dissension among his subjects that finally led to Poland’s downfall in the 18th century. This tends to make him, in the final reckoning, a somewhat tragic figure.

source: britannica