Władysław was elected as the tsar of Russia by the Seven Boyars in 1610, when the Polish army captured Moscow, but did not assume the throne because of his father's position and a popular uprising.

Following his election as king of Poland and grand duke of Lithuania in 1632, he was largely successful in defending the Polish–Lithuanian Commonwealth against foreign invasion, most notably in the Smolensk War of 1632–1634 in which he participated personally.

He gained fame by defeating the Ottoman Empire, strengthening royal power, and reforming the Commonwealth's political system, although he failed at reclaiming the Swedish throne.

The Khmelnytsky Uprising in the east (1648) and the subsequent Swedish invasion ("the Deluge", 1655–1660) weakened the country and diminished Poland's status as a regional power.

[4] Around early 17th century Urszula lost much of her influence, as Władysław gained new teachers and mentors, including such priests as Marek Łętkowski, Gabriel Prowancjusz, and Andrzej Szołdrski and in military matters by Zygmunt Kazanowski.

[10] In 1611-12, silver and gold coins (kopecks) were prematurely stuck in the Russian mints in Moscow and Novgorod with Władysław's titulary Tsar and Grand Prince Vladislav Zigimontovych of all Russia.

[12] The Commonwealth gained some disputed territories in the Truce of Deulino, but Władysław was never able to reign in Russia; the throne during this time was instead held by tsar Michael Romanov.

[18] In Genoa and Venice he was impressed by the local shipyards, and in Pisa he witnessed a specially organized mock naval battle, experiences that resulted in his later attempt to create the Polish–Lithuanian Commonwealth Navy.

[27][28] In the pacta conventa, Władysław pledged himself to fund a military school and equipment; to find a way to fund a navy; to maintain current alliances; not to raise armies, give offices or military ranks to foreigners, negotiate peace treaties, or declare war without the Sejm's approval; not to take a wife without the Senate's approval; to convince his brothers to take an oath to the Commonwealth; and to transfer the profits from the Royal Mint to the Royal Treasury rather than to a private treasury.

Władysław proved to be a good tactician, and his innovations in the use of artillery and fortifications based on Western ideas greatly contributed to the eventual Polish–Lithuanian success.

Muscovy also agreed to pay 20,000 rubles in exchange for Wladyslaw's renunciation of all claims to the tsardom and return of the royal insignia, which were in the Commonwealth possession since the Dymitriads.

During the wars against Ottomans in 1633–1634 Władysław moved the Commonwealth army south of the border with Russia, where under the command of the hetman Stanisław Koniecpolski it forced the Turks to renew a peace treaty.

[35] In the resulting treaty, both countries agreed again to curb the border raids by Cossacks and the Tatars, and the Ottomans confirmed that the Commonwealth to be an independent power, and had not to pay tribute to the Empire.

[39] Thus both sides agreed to sign the Armistice of Stuhmsdorf (Sztumska Wieś) on 12 September 1635, favourable to the Commonwealth, which regained the Prussian territories, and called for a reduction of the Swedish tolls on the maritime trade.

His relationship with the Habsburgs was relatively strong; although he was not above carrying some negotiations with their enemies, like France, he refused Cardinal Richelieu's 1635 proposal of an alliance and a full-out war against them, despite the potential lure of territorial gains in Silesia.

[42] He realized that such a move would cause much unrest in a heavily Catholic Commonwealth, that he likely lacked the authority and power to push such a change of policy through the Sejm, and that the resulting conflict would be very difficult.

His first plan was an attempt to secure a hereditary province within the country, which would not be threatened by the possible power shift following a future royal election; this, however, did not gain sufficient support in the Sejm.

[47] Popular vote and opposition also resulted in the failure of the plan to raise taxes from trade tariffs; here it was not only the nobility but even the merchants and burghers from towns, like Gdańsk (Danzig) who were able to muster enough support (including from foreign powers) to stop the king's reforms.

[48] In fact, the defeat of his plans was so total, that he was forced to make certain conciliatory gestures to the nobility, as the Sejm passed several laws constraining his authority (such as to hire foreign troops), further indicating the limits of royal power in the Commonwealth.

[43] The king's trusted confessor, father Walerian Magni[51] (of Franciscan religious order), and voivode Kasper Doenhoff arrived in Regensburg (Polish: Ratyzbona) on 26 October 1636 with consent and performed negotiations.

[54] Those plans included schemes such as supporting the Holy Roman Emperor's raid on Inflanty in 1639, which he hoped would lead to a war;[55] an attempted alliance with Spain against France in 1640–1641,[56] and in 1641–1643, with Denmark against Sweden.

[61] The border with the Empire was in a near-constant state of low-level warfare; some historians estimate that in the first half of the 17th century, Ottoman raids and wars resulted in the loss (death or enslavement) of about 300,000 Commonwealth citizens in the borderlands.

[62] The war, Władysław hoped, would also solve the problem of unrest among the Cossacks, a militant group living in Ukraine, near the Ottoman border, who could find worth in such a campaign, and turn their attention to fighting for the Commonwealth, instead of against it.

[66] On 9 August 1647, his young son, Sigismund Casimir, then seven years old, suddenly fell ill and died; the death of his only legitimate heir to the throne was a major blow to the king, whose grief prevented his attendance at the boy's funeral held in Kraków.

[81] The column, dedicated to his father, was designed by the Italian-born architect Constantino Tencalla and the sculptor Clemente Molli, and cast by Daniel Tym.

[82] Władysław had many plans (dynastic, about wars, territorial gains: regaining Silesia, Inflanty (Livonia), incorporation of Ducal Prussia, creation of his hereditary dukedom etc.

[73] Though his grand international political plans failed, he did improve the Commonwealth foreign policy, supporting the establishment of a network of permanent diplomatic agents in important European countries.

Despite his support for the Protestants, he did not stop the growing tide of intolerance, either in Poland or abroad, as shown by the fate of the Racovian Academy, or an international disagreement between the faiths.

Władysław suffered continuing difficulties caused by the efforts of the Commonwealth's Sejm (parliament) to check the King's power and limit his dynastic ambitions.

[90] Władysław Czapliński in his biography of the king is more understanding, noting the short period of his reign (16 years) and the weakness of the royal position he was forced to deal with.