Chapter 99: The Second Northern War
The accomplishments of Gustavus Adolphus left Sweden as one of the premier powers of Europe, its territorial extent at its greatest and its maritime horizons burgeoning beyond the confines of the Baltic Sea. Although upon his death his son and successor John IV Sigismund was still a minor, his high chancellor Axel Oxenstierna oversaw the kingdom’s affairs until his death in 1654. By then, John IV Sigismund had grown into the role of a young Swedish king and was ready to fully take the helm of state. Alongside him was the queen and his new wife, Hedwig Eleonora of Holstein-Gottorp, who would become known not only for her beauty but for her strong personality. In 1655, the succession would be secured with the birth of a son, John, and the future looked promising for the Swedish Empire. Growing Swedish power, however, alarmed its neighbors like Denmark-Norway, Poland-Lithuania, and Russia, and tension between Sweden and these neighbors would set the stage for the Second Northern War.
The events that would spark the Second Northern War would begin in West Africa in the Swedish Gold Coast colony. In 1656, Hendrix Carloff was replaced by Johan Filip von Krusenstierna as its governor. An enraged Carloff left the capital of Cabo Corso and entered the service of the Danish Africa Company, using his credentials and experience to quickly become its director-general. returning in January 1658 aboard the Danish privateer Gluckstadt. A brief engagement followed where Carloff captured the fort and established the first foothold of the Danish Gold Coast colony. This incident would give Sweden a casus belli to declare war in June 1658 after attempts to get Denmark to return the fort to the Swedes went nowhere. Holstein-Gottorp would also join the war on the Swedish side, its alliance with the Scandinavian power secured through John IV Sigismund and Hedwig Eleonora’s marriage.
Fort Carlsborg, its capture by Hendrik Carloff sparking the Second Northern War
John IV Sigismund aimed for a swift conflict that would not only return the Danish Gold Coast to Sweden but also see his realm gain further continental territories, ideally Scania. To that end, the Swedish strategy involved quickly overwhelming the Danes from the north and south by Sweden and Holstein-Gottorp respectively. However, this plan wouldn’t pan out as the king had hoped. Initially, the Swedes were quickly able to occupy Scania within the year and their fleet defeated a Danish one off the coast of the island of Bornholm. The following spring, that fleet transported a force of 9,000 led by the king himself near the Danish capital of Copenhagen for an assault upon the city itself. However, the city would not fall easily and a protracted siege began. Additionally, the Danes under their king Frederick III halted and defeated an army led by Christian Albert, the heir to Holstein-Gottorp and the Swedish queen’s younger brother, allowing the Danes to turn back and confront the enemy surrounding Copenhagen. Although the Swedes would repel the Danes, they would soon be scrambling to evacuate from the area due to outside factors.
The swift Swedish advance upon Copenhagen alarmed the kingdom’s other powers, particularly Russia and the Netherlands. The latter had actually signed a defensive pact with Denmark-Norway in 1649 and had only been prevented from joining the war earlier due to the Republic recovering from the 8 year Republican-Orangist factional split. These two powers would enter the war on the Danish side in the late spring of 1659, immediately forcing John IV Sigismund to abandon his siege of Copenhagen to defend Sweden’s borders, particularly its Finnish and Livonian frontiers from Muscovy. The king’s retreat itself was nearly intercepted by a Dano-Dutch fleet which would go on to defeat the Swedish fleet at sea at the Battle of the Sound on June 29th. The anti-Swedish coalition would go on to blockade the Sound, cutting off Sweden from its overseas possessions including New Sweden and the Swedish Gold Coast. Amidst the reversal of fortunes for Sweden, King John II Casimir Vasa of the Polish-Lithuanian Commonwealth also considered joining the war against the Swedes, although his realm’s magnates in the Sejm blocked all proposals to declare war on Sweden.
Painting of the 1659 Battle of the Sound by Jan Abrahamsz Beerstraaten in 1660
With France, both a Dutch and a Swedish ally, refusing to involve itself in the conflict, Sweden turned to England for help with whom it had marriage ties with. Anglo-Dutch economic and political tensions had already begun mounting since the 1640s, especially after England’s passage of the Navigation Act in 1651. As a result, it was no surprise when the English eagerly joined the war on Sweden’s side, primarily to weaken Dutch mercantile power worldwide. The Anglo-Swedish theater of the war would be nearly its own conflict and would be referred to as the 1st Anglo-Dutch War as the wider war would expand into the English Channel and North America. The English entry into the war would prove fortuitous for Sweden, for it not only divided Dutch naval attention between the North Sea and the English coast but also sabotaged the Dutch conquest of New Sweden. In the latter, Peter Stuyvesant, the governor-general of New Netherland, had led an invasion force of several hundred men in September 1659, sailing down the Vasa River and simultaneously using his colonial fleet to blockade Fort Christina. After fierce fighting, New Sweden’s governor Johan Risingh was forced to retreat back into Fort Christina where a siege began. However, English aid soon came from both the mother country and the crown colony of Virginia and at the Battle of the Delaware Bay in April 1660, the Dutch blockade was broken and a land force embarked near the besieged Swedish fortifications, managing to expel Stuyvesant’s men from the area. Intermittent fighting would continue but English support ensured the survival of the Swedish colony from the Dutch.
Back in continental Europe, Russia began an invasion of Swedish Livonia and Ingria, quickly capturing the fortresses of Noteborg, Nyen, Dyneburg, and Kokenhusen. This Muscovite offensive reached its climax when the main Russian army, led by Tsar Alexei Mikhailovich, began besieging the key port of Riga in summer 1659. However, as Moscow lacked a proper army, the Tsar could not cut off the continuous flow of supplies for the heavily outnumbered garrison in the city. Meanwhile, John IV Sigismund was frantically levying men to confront the incursion to his realm’s eastern frontier while also directing manpower to hold down Scania and guard the Swedish-Norwegian border in case a Dano-Norwegian army attempted an invasion. By the time the Swedish king began the voyage from Stockholm to Livonia to relieve Riga, the foreign officers commanding the meager Russian naval presence had defected and forced Tsar Alexei to end the siege. What would follow was a back and forth war between the Swedes and Russians that devastated the countryside and cost both sides heavy casualties. Although the Swedish army was superior to its Russian counterpart in its training, tactics, and technology and generally won most pitched engagements, it was outnumbered and its chief commander, the king himself, was constantly distracted by news from the other fronts of the war. Consequently, the Russians largely kept control of the fortresses and towns they had captured.
Depiction of the siege of Riga in 1658
Mixed outcomes for the anti-Swedish coalition at sea, in Livonia, and in North America contrasted with the swift reversal of fortunes for the duchy of Holstein-Gottorp as the Danes concentrated their efforts towards the former until its chief fortress at Tonning was encircled by an army of 18,000 Danes, Norwegians, and Dutchmen. Swedish relief efforts from its German territories went nowhere and after a year of encirclement, duke Christian Albert was forced to surrender. In the Treaty of Gottorp on December 8th, 1662, the duchy was forced to cede its holdings in Schleswig to Denmark. The Danes were now free to prey upon Swedish Bremen-Verden, Pomerania, and Wismar and suddenly, the Swedes found himself in a precarious situation. Fortunately, Sweden still possessed a cadre of talented commanders, including Field Marshal Carl Gustaf Wrangel. Although up until now having a mixed record in the war, he would lead a Swedish army of 13,000 against a Dano-Dutch force of 17,000 on June 9th, 1662 at the Battle of Gadebusch, damaging the coalition’s hope of weakening Sweden’s position in German lands.
By 1663, both sides were exhausted and saw no path towards outright victory. Therefore, all participating powers chose to negotiate peace. In the subsequent Treaty of Lund, Sweden would regain its lost colony in West Africa but would cede parts of the Livonian and Ingrian interior, which had been lost to Russia [1]. It was forced to return Scania and also recognized the 1661 Treaty of Gottorp and 1662 Treaty of Westminster [2], which had already ended the Anglo-Dutch naval theater of the war. The Second Northern War had several consequences. Firstly, Swedish ambitions in northern Europe had been comprehensively checked by its alarmed neighbors. For the realm to expand further, it would need to overcome its weaknesses. The young John IV Sigismund had been tested on the battlefield and at the negotiating table and had proved its worth, but he had his work cut out for him. Secondly, although on the surface ending in a draw, the Anglo-Dutch conflict proved fortuitous for the English. Although no territorial exchanges occurred between the two powers, England emerged having inflicted damage upon Dutch trade power through the operations of its privateers and managed to arrange maritime terms favorable towards them. Thirdly, the Second Northern War distracted Muscovy from the territorial incursions conducted by the Japanese and the Amur Khanate in Siberia and prevented Russia from reacting accordingly. Just as Russia began looking east to resolve matters, that region would witness geopolitical rivalries boil over within a few years of the Second Northern War.
[1]: The same territorial acquisitions as TTL’s Treaty of Valiesar
[2]: Basically the same as OTL’s Treaty of Westminster of the 1st Anglo-Dutch War