Władysław IV Vasa (1632–1648)
During the reign of Sigismund's son, Władysław IV Vasa, the Cossacks in Ukraine revolted against Poland; wars with Russia and Turkey weakened the country; and szlachta obtained new privileges, mainly exemption from income tax.
Władysław IV aimed to achieve many military goals, including conquests of Russia, Sweden and Turkey. His reign is that of many small victories, few of them bringing anything worthwhile to the Commonwealth. He was once elected a Russian tsar, but never had any control over Russian territories. Like his father, Władysław was involved in Swedish dynastic ambitions. He failed to strengthen the Commonwealth or prevent the crippling events of the Khmelnytsky Uprising and the The Deluge that devastated the Commonwealth from 1648 onward.
Read more about this topic: History Of Poland In The Early Modern Era (1569–1795), House of Vasa