European history is often framed through the relationships of the ‘great powers’. On 12 October 1611, the date of Gustavus Adolphus’s coronation as King of Sweden, his modest kingdom was not counted amongst their number. However, his reign brought a golden age of innovation, influence and expansion – not only in Scandinavia but across Northern Europe. By his death at the Battle of Lützen in 1632, his kingdom had earned its status as a great power, a position it held for a century more.
As soon as he was crowned, Adolphus became a wartime monarch. Sweden was simultaneously fighting Denmark-Norway (the Kalmar War), Russia (the Ingrian war) and Poland. Such wars – a legacy of Charles IX’s reign as King of Sweden – would not be concluded until 1629.
Over this period, Gustavus modernised and improved his army: the sabre was replaced with the wheel lock pistol (allowing for a greater range of attack), whilst the rate of artillery improved was drastically improved. However, the need to conclude the wars of his predecessor meant that the Swedish army was not used for territorial expansion until 1630.
On 6 July 1630, Gustavus Adolphus landed on Usedom, an island off the coast of Pomerania (modern day Northern Germany and Poland), with 14,000 troops, determined to establish control over the Baltic’s southern coast. In beginning the ‘Swedish Intervention’, Gustavus brought war back to continental Europe after a temporary lull in conflict.
Gustavus’s invasion, however, took many by surprise. Ferdinand II – the Holy Roman Emperor – declared in a letter to Adolphus on 18 August 1630 that he was “completely baffled” by the invasion. Ferdinand, ironically, was perhaps the most instrumental in bringing about the invasion, as it seems most likely that it was a fear of Habsburg aggression that drove Gustavus to pre-emptively attack Northern Germany
Indeed, for much of the preceding decade, Ferdinand had been strengthening his presence on the northern coast of the Baltic, threatening not only the economic but also the strategic interests of Sweden in the region. In 1626, one Imperial statesman, Wallenstein, had even sent troops to fight against Sweden in the Polish–Swedish War.
The Habsburg siege of the free city of Stralsund (Pomerania) in May 1628, hardly helped the situation: Gustavus sent in troops, proving that Sweden was prepared to go to military lengths to prevent Habsburg domination on the Baltic shore. As a further response, in December, Gustavus officially signalled his frustration with the empire’s conduct and suggested that military action might follow. And, finally, Gustavus’ sudden desperation in 1629 for a peace treaty with Poland – the Truce of Altmark – which would free up troops vital to either a defensive or offensive war, was the final, decisive, signal that war was imminent.
When Gustavus did land in Northern Germany – despite the fact that the invasion had been justified in many contemporary pamphlets as an attack in defence of the Protestant faith – the king received only limited support. The Protestant Duke of Pomerania, Bogislaw XIV, for instance, ordered the gates of Stettin to be closed with the explicit purpose of keeping out the Swedes.
As a result, Gustavus assumed a more assertive, even imperial foreign policy, demanding concessions and support from local territories. In the case of Bogislaw, for example, Adolphus declared that the region belonged to the Swedish king by the right of conquest. Although after further negotiation the territory was not immediately ceded, Article 14 of the agreement with Pomerania allowed Sweden full control of the area after the death of the Duke. Sweden’s territorial expansion had begun.
Perhaps the most important signal of Gustavus’s changing foreign policy, though, came when he proclaimed in late 1631 that all Swedish occupied lands were Swedish fiefs that would revert to Sweden if the respective rulers died without heirs. This is not to mention the financial contributions the king demanded: in 1632, for instance, he collected 240,000 thalers from Augsburg (annual taxes usually remained below 50,000). Similarly, Wurzburg was forced to hand over 150,000 thalers in October 1631.
Whilst such financial support aided the Swedish war effort, it did not guarantee success. Although the early period saw Gustavus’s forces roll across Northern German – at one point holding about half of the member states of the Holy Roman Empire – Gustavus’ innovative tactics and modern technologies were soon outweighed by the sheer might of the Holy Roman Empire. Adolphus himself was killed in 1632 at the Battle of Lützen.
The Peace of Prague in 1635, consequently, when the Holy Roman Empire made peace with almost all of its German enemies, looked like the end of Swedish participation in the war, and, potentially, the end of Swedish pre-eminence in Europe. However, the continued assistance of France – a staunch enemy of the Holy Roman Empire – allowed Sweden to preserve its status as a major European power.
Indeed, at the Peace of Westphalia (the treaty ending the Thirty Years’ War), the still-influential Sweden won major territorial concessions. It gained German territories as fiefs of the Holy Roman Empire, allowing the nation a vote in the Imperial Diet and enabling it to control the Lower Saxon Kreis. Sweden was also granted a 20,000,000 Riksdaler war indemnity, further establishing the nation as a military powerhouse.
Peace, however, did not last long. In 1655, Sweden invaded Greater Poland, which had been devastated by wars against the Tsardom of Russia and the Polish-Lithuanian Commonwealth, in order to finance their swelling army through plunder. After the congeries of alliances and agreements were triggered, the regional conflict became the ‘Second Northern War’. The military strength of the Swedes – so overwhelming were they in Poland that it has since been termed the ‘Swedish Deluge’ – was a warning for what was to come in subsequent years, as Sweden moved towards the zenith of their power.
As a result of such conquests. the territory controlled by Sweden was double what it is now By the middle of the 17th Century, Sweden was the third largest country in Europe, trailing only Spain and Russia. Perhaps surprisingly, part of this was overseas: between 1638 and 1663, Sweden had overseas colonies, in North America with the territory of New Swede and also along the Gold Coast in Africa.
Such prosperity, sadly, was not indefinite. The tide ultimately began to turn as its Scandinavian rivals rallied against Sweden, no longer supported by France. In 1700, Denmark-Norway, Poland, and Russia declared war on Sweden. Although there were some successes – Charles dethroned the King of Poland in 1706, for instance – the Russian victory at the Battle of Poltava consigned Sweden to return to its former status as a modest power.
Sweden was one of the most influential and powerful countries in determining the course of 17th Century European history. That the Sweden of today seems a world away from being able to rival the greatest European powers is a testament to the inconstant nature of great power relations.
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