The Polish–Swedish union was a short-lived

personal union A personal union is a combination of two or more monarchical states that have the same monarch while their boundaries, laws, and interests remain distinct. A real union, by contrast, involves the constituent states being to some extent in ...

between the

Polish–Lithuanian Commonwealth The Polish–Lithuanian Commonwealth, also referred to as Poland–Lithuania or the First Polish Republic (), was a federation, federative real union between the Crown of the Kingdom of Poland, Kingdom of Poland and the Grand Duchy of Lithuania ...

and the Kingdom of Sweden between 1592 and 1599. It began when

Sigismund III Vasa Sigismund III Vasa (, ; 20 June 1566 – 30 April 1632 N.S.) was King of Poland and Grand Duke of Lithuania from 1587 to 1632 and, as Sigismund, King of Sweden from 1592 to 1599. He was the first Polish sovereign from the House of Vasa. Re ...

, elected

King of Poland Poland was ruled at various times either by dukes and princes (10th to 14th centuries) or by kings (11th to 18th centuries). During the latter period, a tradition of Royal elections in Poland, free election of monarchs made it a uniquely electab ...

and Grand Duke of Lithuania, was crowned

King of Sweden The monarchy of Sweden is centred on the monarchical head of state of Sweden,See the #IOG, Instrument of Government, Chapter 1, Article 5. by law a constitutional monarchy, constitutional and hereditary monarchy with a parliamentary system.Parl ...

following the death of his father John III. The union ended following a civil war in Sweden in which he lost the crown to his uncle, who eventually became Charles IX. Sigismund afterwards returned to

Warsaw Warsaw, officially the Capital City of Warsaw, is the capital and List of cities and towns in Poland, largest city of Poland. The metropolis stands on the Vistula, River Vistula in east-central Poland. Its population is officially estimated at ...

and pursued a war against his former realm.

History

Prelude

After the death of John III, his son Sigismund became heir to the throne of Sweden. Sigismund at that time was already the elected King of Poland, and had so been since 1587. Sigismund certainly valued the Swedish throne and upon learning about the death of his father, and the pretensions to the throne of his uncle, Duke Charles of Södermanland, he asked the

Sejm The Sejm (), officially known as the Sejm of the Republic of Poland (), is the lower house of the bicameralism, bicameral parliament of Poland. The Sejm has been the highest governing body of the Third Polish Republic since the Polish People' ...

(Polish parliament) for permission to leave the Commonwealth and go to Sweden, where he could secure the Swedish crown. The Sejm gave him permission, and on 3 August 1593, Sigismund, accompanied by his wife, Anna of Habsburg, and other followers, departed for Sweden. In Sweden, he encountered a serious problem due to his religion, as Sigismund was a devoted

Catholic The Catholic Church (), also known as the Roman Catholic Church, is the List of Christian denominations by number of members, largest Christian church, with 1.27 to 1.41 billion baptized Catholics Catholic Church by country, worldwid ...

, and most of the Swedish population (including Charles) had converted to

Lutheranism Lutheranism is a major branch of Protestantism that emerged under the work of Martin Luther, the 16th-century German friar and Protestant Reformers, reformer whose efforts to reform the theology and practices of the Catholic Church launched ...

. There were fears that Sigismund, if elected king, would support the Catholics against the Protestants. At this period Duke Charles and his Protestant allies were clearly outnumbered by the supporters of Sigismund. Nevertheless, immediately after King John’s death, a

synod A synod () is a council of a Christian denomination, usually convened to decide an issue of doctrine, administration or application. The word '' synod'' comes from the Ancient Greek () ; the term is analogous with the Latin word . Originally, ...

summoned to

Uppsala Uppsala ( ; ; archaically spelled ''Upsala'') is the capital of Uppsala County and the List of urban areas in Sweden by population, fourth-largest city in Sweden, after Stockholm, Gothenburg, and Malmö. It had 177,074 inhabitants in 2019. Loc ...

by Duke Charles rejected the new liturgy and drew up an anti-Catholic confession of faith on 5 March 1593.

Holy Scripture Religious texts, including scripture, are texts which various religions consider to be of central importance to their religious tradition. They often feature a compilation or discussion of beliefs, ritual practices, moral commandments and ...

and the three primitive creeds were declared to be the true foundations of Christian faith, and the

Augsburg confession The Augsburg Confession (), also known as the Augustan Confession or the Augustana from its Latin name, ''Confessio Augustana'', is the primary confession of faith of the Lutheranism, Lutheran Church and one of the most important documents of th ...

was adopted, on 9 January 1594, in

. Sigismund was confronted by the representatives of the

Lutherans Lutheranism is a major branch of Protestantism that emerged under the work of Martin Luther, the 16th-century German friar and reformer whose efforts to reform the theology and practices of the Catholic Church launched the Reformation in 15 ...

and the lower

nobility Nobility is a social class found in many societies that have an aristocracy. It is normally appointed by and ranked immediately below royalty. Nobility has often been an estate of the realm with many exclusive functions and characteristics. T ...

. Pressured by the political situation, and amidst the turmoil which included Sigismund's Catholic entourage and their Lutheran opponents, he eventually agreed on February 19, to guarantee

religious freedom Freedom of religion or religious liberty, also known as freedom of religion or belief (FoRB), is a principle that supports the freedom of an individual or community, in public or private, to manifest religion or belief in teaching, practice ...

to the Protestants, and forbade the Catholics from public demonstrations of their faith and from holding high offices.

Union

The agreement of 19 February seemed to have calmed the situation; Sigismund was crowned in the Cathedral of Uppsala and became the

king of Sweden The monarchy of Sweden is centred on the monarchical head of state of Sweden,See the #IOG, Instrument of Government, Chapter 1, Article 5. by law a constitutional monarchy, constitutional and hereditary monarchy with a parliamentary system.Parl ...

. The

Kingdom of Sweden Sweden, formally the Kingdom of Sweden, is a Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic country by both area ...

was now in a

with

. In July, Sigismund left Sweden in the hands of the regency council and returned to Poland. Sweden was to be ruled jointly by the

Privy Council of Sweden The Council of the Realm, or simply The Council ( or : sometimes in ), was a cabinet of medieval origin, consisting of magnates () which advised, and at times co-ruled with, the King of Sweden. The 1634 Instrument of Government, Sweden's fir ...

and Sigismund's uncle Duke Charles. Sigismund, however, reneged on his earlier promises, opening Catholic schools, and giving Catholics prominent posts. Charles in turn did not give up on acquiring the Swedish throne and pursued his own political agenda. On 18 May 1595 he signed a treaty of Teusina with

Muscovy Muscovy or Moscovia () is an alternative name for the Principality of Moscow (1263–1547) and the Tsardom of Russia (1547–1721). It may also refer to: *Muscovy Company, an English trading company chartered in 1555 *Muscovy duck (''Cairina mosch ...

, ending the Russo-Swedish War (1590–95) by agreeing borders ''

status quo ante bellum The term is a Latin phrase meaning 'the situation as it existed before the war'. The term was originally used in treaties to refer to the withdrawal of enemy troops and the restoration of prewar leadership. When used as such, it means that no ...

'' around the

Gulf of Finland The Gulf of Finland (; ; ; ) is the easternmost arm of the Baltic Sea. It extends between Finland to the north and Estonia to the south, to Saint Petersburg—the second largest city of Russia—to the east, where the river Neva drains into it. ...

(

Ingria Ingria (; ; ; ) is a historical region including, and adjacent to, what is now the city of Saint Petersburg in northwestern Russia. The region lies along the southeastern shore of the Gulf of Finland, bordered by Lake Ladoga on the Karelian ...

) and recalling some of Sigismund's supporters posts (among them, Admiral

Klaus Fleming Baron Klaus Eriksson Fleming (; 1535 in Pargas – 13 April 1597 in Pohja) was a Finnish-born member of the Swedish nobility and admiral, who played an important role in Finnish and Swedish history during the rise of Sweden as a Great Po ...

). That went against Sigismund's plans, as he had promised in his

pacta conventa ''Pacta conventa'' (Latin for "articles of agreement") was a contractual agreement entered into between the "Polish nation" (i.e., the szlachta (nobility) of the Polish–Lithuanian Commonwealth) and a newly elected king upon his "free electi ...

during his election to the Commonwealth throne to cede the Duchy of Estonia to the Commonwealth from Sweden, and in turn compensate Sweden with territory acquired from Muscovy. In 1595, Charles openly disobeyed the king by calling the

Riksdag of the Estates Riksdag of the Estates (; informally ) was the name used for the Estates of Sweden when they were assembled. Until its dissolution in 1866, the institution was the highest authority in Sweden next to the King. It was a Diet made up of the Fou ...

to session in

Söderköping Söderköping is a Urban areas in Sweden, locality and the seat of Söderköping Municipality, Östergötland County, Sweden with 6,992 inhabitants in 2010. Söderköping is, despite its small population, for historical reasons normally still refe ...

. The Riksdag of 1595, proclaimed him

regent In a monarchy, a regent () is a person appointed to govern a state because the actual monarch is a minor, absent, incapacitated or unable to discharge their powers and duties, or the throne is vacant and a new monarch has not yet been dete ...

though King Sigismund had previously refused him that office. Supported by many

Protestants Protestantism is a branch of Christianity that emphasizes Justification (theology), justification of sinners Sola fide, through faith alone, the teaching that Salvation in Christianity, salvation comes by unmerited Grace in Christianity, divin ...

and most of the lower classes, he was opposed by most of the nobility, Catholics, the area constituting modern Finland, and most of the population of Stockholm. Sweden was now on the verge of

civil war A civil war is a war between organized groups within the same Sovereign state, state (or country). The aim of one side may be to take control of the country or a region, to achieve independence for a region, or to change government policies.J ...

. Duke Charles sought to end the conflict by military means, but gained little support within the Privy Council. The new Riksdag he summoned at

Arboga Arboga () is a urban areas of Sweden, locality and the seat of Arboga Municipality in Västmanland County, Sweden with 10,989 inhabitants in 2020. Overview The city of Arboga is known to have existed as a town since the 13th century but the are ...

in 1597 – again despite the King's orders – saw few participants, and only one from the Privy Council. Even so, Duke Charles did not achieve support for his military action, but initiated it nonetheless. Parts of southern Sweden were successfully taken. Several of the Privy Council members fled to Poland to convince Sigismund to take counteractions. Sigismund sent a

diplomatic mission A diplomatic mission or foreign mission is a group of people from a state or organization present in another state to represent the sending state or organization officially in the receiving or host state. In practice, the phrase usually denotes ...

, in an attempt to solve the conflict by negotiations. Charles at first looked ready to negotiate but in fact he was playing for time, trying to confirm his power at another Riksdag (in

), recruiting

peasants A peasant is a pre-industrial agricultural laborer or a farmer A farmer is a person engaged in agriculture, raising living organisms for food or raw materials. The term usually applies to people who do some combination of raising f ...

for his army, and isolating Sigismund's followers. In 1598, the Sejm gave Sigismund the go-ahead to wage a military campaign against his opponents in Sweden; however it refused to give him significant support. Sigismund's army was composed mostly of

mercenaries A mercenary is a private individual who joins an War, armed conflict for personal profit, is otherwise an outsider to the conflict, and is not a member of any other official military. Mercenaries fight for money or other forms of payment rath ...

(Germans and Hungarians), supported by a relatively small Polish force (although with some

artillery Artillery consists of ranged weapons that launch Ammunition, munitions far beyond the range and power of infantry firearms. Early artillery development focused on the ability to breach defensive walls and fortifications during sieges, and l ...

). Sigismund's campaign was poorly planned. He was unable to coordinate his troop movements with his supporters, particularly Fleming who was supposed to attack Charles from Finland. After initial successes (the taking of

Kalmar Kalmar (, , ) is a city in the southeast of Sweden, situated by the Baltic Sea. It had 41,388 inhabitants in 2020 and is the seat of Kalmar Municipality. It is also the capital of Kalmar County, which comprises 12 municipalities with a total of ...

and defeating Charles' troops at Stegeborg), Sigismund's forces were defeated on 25 September 1598 at the

Battle of Stångebro The Battle of Stångebro, or the Battle of Linköping, took place at Linköping, Sweden, on 25 September 1598 (O.S.) and effectively ended the personal union between Sweden and the Polish–Lithuanian Commonwealth, that had existed since 1592. ...

(also known as the battle of Linköping). Sigismund was captured and forced to hand over some of his followers such as the Chancellor of Sweden,

Erik Sparre Erik Larsson Sparre (born Erik Larsson; also known as Erik Gyllensparre, Eric Sparre, or Erik Sparre of Rossvik; 13 July 1550 – 20 March 1600) was a Swedish noble, statesman, diplomat, and political theorist who served as Privy Councilor fro ...

. In May 1599, Charles' forces captured the last fortress held by Sigismund,

. On 24 July 1599, the Riksdag in Stockholm officially dethroned Sigismund. The new King of Sweden was

Charles IX of Sweden Charles IX, also Carl (; 4 October 1550 – 30 October 1611), reigned as King of Sweden from 1604 until his death. He was the youngest son of King Gustav I () and of his second wife, Margaret Leijonhufvud, the brother of King Eric XIV and of ...

, and the Polish–Swedish union was dissolved after barely seven years of existence. In March 1600, some of Sigismund's supporters were executed, including five

senator A senate is a deliberative assembly, often the upper house or Legislative chamber, chamber of a bicameral legislature. The name comes from the Ancient Rome, ancient Roman Senate (Latin: ''Senatus''), so-called as an assembly of the senior ...

s, in an event known as the Linköping Bloodbath ().

Aftermath

Sigismund, who was allowed to return to Poland, did not relinquish his desire to regain the throne of Sweden. This attitude led to a series of

Polish–Swedish wars This is a List of wars between the Polish–Lithuanian Commonwealth and Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to ...

, that culminated during the reign of his son, John II Casimir of Poland, with the giant Swedish invasion of Poland known as the Deluge.

Geography

At the time of the union, the coastline of Poland stretched from Pomerania in the southwest to

Pärnu Pärnu () is the fourth-largest city in Estonia. Situated in southwest Estonia, Pärnu is located south of the Estonian capital, Tallinn, and west of Estonia's second-largest city, Tartu. The city sits off the coast of Pärnu Bay, an inlet of ...

in the northeast (modern-day Estonia). The Swedish coastline stretched from

Brömsebro Brömsebro () is a bimunicipal village situated in Karlskrona Municipality, Blekinge County and Torsås Municipality, Kalmar County in south-eastern part of country Sweden with 213 inhabitants in 2005. Two Dano-Swedish treaties were signed in Brö ...

in the west, around the northern part of the Baltic, down to

. Thus the time of the Polish–Swedish union was unique in that the

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by the countries of Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden, and the North European Plain, North and Central European Plain regions. It is the ...

effectively became an internal sea of this superstate. A somewhat similar situation exists as of 2024, in that the Baltic Sea is now surrounded by NATO, with the sole exception of

Kaliningrad Kaliningrad,. known as Königsberg; ; . until 1946, is the largest city and administrative centre of Kaliningrad Oblast, an Enclave and exclave, exclave of Russia between Lithuania and Poland ( west of the bulk of Russia), located on the Prego ...

and

Leningrad oblast Leningrad Oblast (, ; ; ) is a federal subjects of Russia, federal subject of Russia (an oblast). The oblast has an area of and a population of 2,000,997 (2021 Russian census, 2021 Census); up from 1,716,868 recorded in the 2010 Russian census ...

References