Second Northern War in the context of "Charles X Gustav of Sweden"

The Khmelnytsky Uprising, also known as the Cossack–Polish War, Khmelnytsky insurrection, or the National Liberation War, and Cossack Revolution, was a successful Cossack rebellion with elements of religious war that took place between 1648 and 1657 in the eastern territories of the Polish–Lithuanian Commonwealth, resulting in Cossack victory and the creation of the Cossack Hetmanate in present-day Ukraine. Under the command of Cossack Hetman Bohdan Khmelnytsky, the Zaporozhian Cossacks, allied with the local Ruthenian (Ukrainian) peasantry and initially the Crimean Tatars, fought against the Commonwealth's forces. The war was accompanied by mass atrocities committed by Cossacks against prisoners of war and the civilian population, especially Poles, Jews, Roman Catholic and Ruthenian Uniate clergy, as well as savage reprisals by the Polish szlachta and the loyalist Jeremi Wiśniowiecki, the voivode of Ruthenian descent (military governor) of the Ruthenian Voivodeship.

The uprising has a symbolic meaning in the history of Ukraine's relationship with Poland and Russia. It ended the Polish Catholic szlachta's domination over the Ukrainian Orthodox population; at the same time, it led to the eventual incorporation of eastern Ukraine into the Tsardom of Russia initiated by the 1654 Pereiaslav Agreement, whereby the Cossacks would swear allegiance to the tsar while retaining a wide degree of autonomy. The event triggered a period of political turbulence and infighting in the Hetmanate known as the Ruin. The success of the anti-Polish rebellion, along with internal conflicts in Poland and concurrent invasions waged by Russia and Sweden against the Poles, ended the Polish Golden Age and caused a secular decline of Polish power during the period known as "the Deluge".

Michiel Adriaenszoon de Ruyter (IPA: [miˈxil ˈaːdrijaːnˌsoːn də ˈrœytər]; 24 March 1607 – 29 April 1676) was a Dutch States Navy officer. His achievements with the Dutch navy during the Anglo-Dutch Wars earned him the reputation as the greatest naval commander of 17th century Europe.

De Ruyter came from a modest background in Zeeland and began seafaring from an early age; by the age of 30 he had become a shipmaster in the Dutch merchant fleet. In 1641, De Ruyter briefly served as a rear admiral during the Portuguese Restoration War, after which he returned to a prosperous merchant career for a decade before retiring to his hometown of Vlissingen. On the outbreak of the First Anglo-Dutch War in 1652, De Ruyter accepted a command in the Dutch Navy under lieutenant admiral Maarten Tromp, distinguished himself and was promoted to vice admiral at the end of the war. In 1655, he took part in the Second Northern War on the side of Denmark-Norway against Sweden.

The Treaty of Roskilde was negotiated at Høje Taastrup Church and was concluded on 26 February (OS) or 8 March 1658 (NS) during the Second Northern War between Frederick III of Denmark–Norway and Karl X Gustav of Sweden in the Danish city of Roskilde. After a devastating defeat, Denmark–Norway was forced to give up a third of its territory to save the rest, the ceded lands comprising Blekinge, Bornholm, Bohuslän, Scania and Trøndelag, as well as Halland.

After the treaty entered into force, Swedish forces continued to campaign in the remainder of Denmark–Norway, but had to withdraw from the Danish isles and Trøndelag in the face of a Dano–Norwegian and Dutch alliance. The Treaty of Copenhagen restored Bornholm to Denmark and Trøndelag to Norway in 1660, while the other provinces transferred in Roskilde remained Swedish.

The history of Lithuania dates back to settlements founded about 10,000 years ago, but the first written record of the name for the country dates back to 1009 AD. Lithuanians, one of the Baltic peoples, later conquered neighboring lands and established the Grand Duchy of Lithuania in the 13th century (and also a short-lived Kingdom of Lithuania). The Grand Duchy was a successful and lasting warrior state. It remained fiercely independent and was one of the last areas of Europe to adopt Christianity (beginning in the 14th century). A formidable power, it became the largest state in Europe in the 15th century spread from the Baltic Sea to the Black Sea, through the conquest of large groups of East Slavs who resided in Ruthenia.

In 1385, the Grand Duchy formed a dynastic union with Poland through the Union of Krewo. Later, the Union of Lublin (1569) created the Polish–Lithuanian Commonwealth. During the Second Northern War, the Grand Duchy sought protection under the Swedish Empire through the Union of Kėdainiai in 1655. However, it soon returned to being a part of the Polish–Lithuanian state, which persisted until 1795 when the last of the Partitions of Poland erased both independent Lithuania and Poland from the political map. After the dissolution, Lithuanians lived under the rule of the Russian Empire until the 20th century, although there were several major rebellions, especially in 1830–1831 and 1863.

The Polish–Russian War of 1654–1667 was a major conflict between the Tsardom of Russia and the Polish–Lithuanian Commonwealth. Between 1655 and 1660, the Swedish invasion was also fought in the Polish–Lithuanian Commonwealth and so the period became known as "The Deluge".

The Commonwealth initially suffered defeats, but it regained its ground and won several decisive battles. However, its plundered economy was not able to fund the long conflict. Facing internal crisis and civil war, the Commonwealth was forced to sign a truce. The war ended with significant Russian territorial gains and marked the beginning of the rise of Russia as a great power in Eastern Europe.

The Deluge was a series of mid-17th-century military campaigns in the Polish–Lithuanian Commonwealth. In a stricter sense, the term refers to the Swedish invasion and occupation of the Commonwealth as a theatre of the Second Northern War (1655–1660) only; in Poland and Lithuania this period is called the Swedish Deluge (Polish: potop szwedzki, Lithuanian: švedų tvanas, Swedish: svenska syndafloden), or less commonly the Russo–Swedish Deluge (Polish: Potop szwedzko-rosyjski) due to the simultaneous Russo-Polish War. In a wider sense, it applies to the period between the Khmelnytsky Uprising of 1648 and the Truce of Andrusovo in 1667, comprising the Polish theatres of the Russo-Polish and Second Northern Wars. The term "deluge" (potop in Polish) was popularized by Henryk Sienkiewicz in his novel The Deluge (1886).

During the wars the Commonwealth lost approximately one third of its population as well as its status as a great power due to invasions by Sweden and Russia. According to Professor Andrzej Rottermund, manager of the Royal Castle in Warsaw, the destruction of Poland in the Deluge was more extensive than the destruction of the country in World War II. Rottermund claims that Swedish invaders robbed the Commonwealth of its most important riches, and most of the stolen items never returned to Poland. Warsaw, the capital of the Polish–Lithuanian Commonwealth, was destroyed by the Swedes, and out of a pre-war population of 20,000, only 2,000 remained in the city after the war. According to the 2012 Polish estimates, the material damage caused by the Swedish army amounted to 4 billion złotys. 188 cities and towns, 186 villages, 136 churches, 89 palaces, and 81 castles were completely destroyed in Poland.

The Treaty of Bromberg (German: Vertrag von Bromberg, Latin: Pacta Bydgostensia) or Treaty of Bydgoszcz was a treaty between John II Casimir Vasa and Elector Frederick William of Brandenburg-Prussia that was ratified at Bromberg (Bydgoszcz) on 6 November 1657. The treaty had several agreements, including the Treaty of Wehlau, signed on 19 September 1657 by the Brandenburg–Prussian and Polish–Lithuanian envoys in Wehlau (Welawa, now Znamensk). Thus, the Treaty of Bromberg is sometimes referred to as treaty of Wehlau-Bromberg or Treaty of Wehlau and Bromberg (Polish: traktat welawsko-bydgoski).

In exchange for military aid in the Second Northern War and the return of Ermland (Ermeland, Warmia) to Poland, the Polish-Lithuanian monarch granted the Hohenzollern dynasty of Brandenburg hereditary sovereignty in the Duchy of Prussia, pawned Draheim (Drahim) and Elbing (Elbląg) to Brandenburg and handed over Lauenburg and Bütow Land to the Hohenzollerns as a hereditary fief.

The Treaty or Peace of Oliva (Polish: Pokój Oliwski; Swedish: Freden i Oliva; German: Vertrag von Oliva) was one of the peace treaties ending the Second Northern War (1655–1660). It was signed on 3 May [O.S. 23 April] 1660. The Treaty of Oliva, the Treaty of Copenhagen in the same year, and the Treaty of Cardis in the following year marked the high point of the Swedish Empire.

At Oliwa (Oliva), Poland, peace was made between Sweden, the Polish–Lithuanian Commonwealth, the Habsburgs and Brandenburg-Prussia. Sweden was accepted as sovereign in Swedish Livonia, Brandenburg was accepted as sovereign in Ducal Prussia and John II Casimir Vasa withdrew his claims to the Swedish throne but was to retain the title of a hereditary Swedish king for life. All occupied territories were restored to their prewar sovereigns. Catholics in Livonia and Prussia were granted religious freedom.