[POTN] 2.8 - The Northern Clouds of War

The Russian invasion of the Commonwealth in July 1654 was a great surprise for the Swedish government and Riksdag. A large army, compromising over forty thousand men, crossed the Russo-Polish border and laid siege to Smolensk. By August, the number of Russian soldiers in the Commonwealth had spiked to over seventy thousand. The Lithuanian part of the Commonwealth, headed by the Calvinist Hetman, Janusz Radziwiłł, tried to stage a resistance to the invading Russian forces.

Nonetheless, repeated defeats suffered by the Lithuanian forces meant they were neutralised temporarily, and the Russians took the city of Smolensk in late September.

By this time, the central government of the Commonwealth was largely dysfunctional, and the eastern peasantry, largely Orthodox, provided crucial support for the Russians against the Catholic government. While the main Russian forces were besieging Smolensk, the other Russians forces achieved great success on both flanks. In the south, with the help from the Hetmanate allies, the Russians were able to reach up to the Dnieper, with relatively light casualties.

In the north, the Russians quickly took the cities of Nevel and Polotsk after the start the invasion, with Vitebsk also falling in November after a siege. By the turn of the year, the Russian army had already reached the Polish-Swedish border in Livonia, alerting the Swedish forces. Stockholm gave the order for the troops at the border to be prepared for a war anytime, but the Russians did not cross the border into Swedish Livonia.

With assistance from the Hetmanate, many Russian forces also crossed the Dnieper in the autumn. By January 1655, much of Volhynia was under Russian control, with only minimal resistance on the way. Many Orthodox serfs, long oppressed by the Catholic landowners, were eager to seek better lives, and thus welcomed the Russian invaders with open arms. The few Polish troops were unable to regain control and were overrun by the Russians easily.

In late January 1655, the Commonwealth finally responded. Janusz Radziwiłł led a counter-offensive in eastern Lithuania, stopping the Russians from advancing more while holding them to a stalemate. The Lithuanian forces besieged Mogilev, occupied by the Russians, in February 1655, but were unable to defeat the Russians decisively.

In the south, the Polish state also raised large armies, numbering over thirty thousand men, in order to retake the territories occupied by the Russians. They managed to bring some success before the spring of 1655, killing thousands of Russians, but themselves also suffered very high casualties. The Crimean Khanate, and their Tatar Muslim population, turned out to be the only reliable ally of the Commonwealth. The Holy Roman Empire, still recovering from the Thirty Years' War, would not send men to relief the Commonwealth.

The Poles and the Tatars temporarily pushed the Russians back in Volhynia in early 1655, stopping their offensive that lasted for months. However, no decisive result was reached, and the Russians remained in Commonwealth territories near the Hetmanate. Tsar Alexei, in Moscow, was very alarmed after receiving news about the Polish gains in the war. He ordered to launch a massive offensive into the Commonwealth, seeking to turn the tide around in favour of the Russians, and to destroy the Commonwealth for once and for all. The Lithuanians were no match for the renewed Russian strength, and crumbled under the offensive. Radziwiłł was forced to lift his siege on Mogilev in May, and the Lithuanian forces began retreating.

The Lithuanians offered little resistance from then on, and the city of Minsk surrendered in early July. That was followed by the Lithuanian capital of Vilnius in late July, and the cities of Kaunas and Grodno in August. In the south, the cities of Pinsk fell in June, and the Russian and Hetmanate forces entered Galicia, eager to continue their conquests.

In Stockholm, the government was very concerned about the situation in the Commonwealth after the birth of the Crown Prince. King Gustav ordered for all the military to prepare for war in February 1655, with Pomerania, Estonia, and Livonia put under mobilisation laws. The Swedes also began hiring mercenaries from all over the Empire, promising them large amount of loots following the invasion. Gustav himself, despite avoiding the question for months, admitted in private that he had decided for war in March 1655.

Princess Kristina was highly dismayed, but she decided that it wasn't the best time for her to intervene following the Riksdag dissolving scandal and the conversion scandal in the previous year.

By April, the Swedish military was ready for war. Thousands of men, compromising of both Swedes and German mercenaries, were on guard on the Swedish-Polish borders in both Pomerania and Livonia, ready to cross the border when the order from Stockholm came.

Gustav, however, was wary of a sudden Brandenburger backstabbing should all Swedish troops invade the Commonwealth. After all, it was obvious that the Elector of Brandenburg, Friedrich Wilhelm, was not content with Sweden gaining control of the entire Pomerania with him only receiving monetary compensation, and could seek to take Pomerania should Swedish defense in the area appear vulnerable.

In May, after appointing Queen Henrietta as Regent, Gustav travelled to Stettin personally, and met a Brandenburger delegation there. After some negotiations, a meeting between Gustav and the Elector was arranged in early June in the Brandenburger border town of Neuruppin.

On 9th June, 1655, Gustav and Friedrich Wilhelm, met each other for the first time in Neuruppin. Following some threats and incentives from Gustav's side, the Elector finally relented, in fear of the Swedes abandoning their Polish ambitions and turn on his realms instead. They signed the Secret Treaty of Neuruppin, detailing the following:

1) The realms of Brandenburg and Prussia shall join any upcoming Swedish conflicts with the Polish-Lithuanian Commonwealth on the Swedish side, providing military support.

2) In return, after a Polish defeat, the Duchy of Prussia shall be released from Polish fealty. The Elector, as the Duke of Prussia, shall no longer hold loyalty to the King of Poland, and the Duchy no longer a Polish fief. Sweden shall immediately recognise the sovereignty of the Duchy of Prussia, before the upcoming war took place.

3) The Duchy of Prussia shall receive the Polish region of Ermland and also the land around Marienburg in the event of a Polish defeat. The new Polish-Prussian border, recognised by Sweden, shall be from the Vistula River delta, along the Vistula River, until the town of Marienwerder.

4) The Electorate of Brandeburg and the Duchy of Prussia conclude a defensive union with the Kingdom of Sweden. For the duration of the war against the Polish-Lithuanian Commonwealth, the Swedish forces shall be allowed to enter the Duchy of Prussia, as long as civilians are protected from harm.

After the signing, Gustav returned to Stettin, finalising the war plans against the Commonwealth with Prince Karl, his brother Prince Adolf Johan, along with several field marshals. By late June, the Swedish army was more than ready for war, all divisions awaiting Gustav's long-anticipated order to attack.