Sweden's empire was in serious danger. All but the most delusional generals and nobles in Stockholm knew this, but the problem was that there was little they could do to stem the tide of enemy soldiers. Russia began the year of 1712 by continuing their advance, taking the cities of Kristinestad, Vassa, Lapola, and Nykarleby in just the first 3 months of 1712, even as Russian casualties rose from desperate Swedish resistance as well as Stenbock's rather effective defense tactics. Even as the Swedish raised more troops, they never managed to reach the level of quality like the troops lost at Poltava. The Russians seemed to be unstoppable at the moment, heavily outnumbering the Swedes and winning every battle they fought. Many on both sides believed that Finland would be completely in Russian hands by the end of the year, unless a miracle happened that did to the Russians what the Russians had done to Sweden at Poltava. It would never come. The Russian offensive in 1712 ended with them taking the city of Uleaborg, though this last drive of the year did result in supply lines being overstretched and the soldiers being very exhausted.
Further southwest, the Danish were now ready to avenge their defeat at Helsingborg 2 years prior. Having gathered enough men to take the war to Swedish soil (even though this did require them to withdraw a large amount of their volunteers that they'd sent the Anglo-Dutch army [1]), the Danish began with an attack on Malmo on August 6, 1712, with some 25,000 Danish facing just 11,200 Swedish. The Swedish managed to inflict disproportionate casualties on the Danish invaders, but the city was eventually taken after a week of nasty fighting. This victory (along with another offensive coming from Norway consisting of 9,500 men aimed at taking Goteburg) let the Danish gradually advance throughout their former province of Scania. By the end of the year, the cities of Goteburg and Kalmar were under siege, with there not being enough young Swedish men to stop both the Danish (who were expecting Saxon reinforcements to arrive soon) and the Russians (who were rampaging across Finland).
In 1713, the Russians continued their attack by taking Tornea in late January, even though it did cost them heavily due to Swedish preparations and the monstrous Finnish winter. They then proceeded to launch naval attacks across the Swedish coasts, with mixed results (some being successful while others ended in a lot of Russian sailors sleeping beneath the waves). On May 6, 1713, a Russian offensive of 40,000 men along with slight naval support managed to take Lulea, marking the first major Russian victory on true Swedish soil. This did nothing for the nerves of the Swedish queen or the generals, even though the Russians were forced to stop for the rest of the year as a result of severe over-extension of supply lines as well as Swedish resistance becoming fiercer (after all, the soldiers knew that this was now on their soil, and that the Russians didn't exactly have a merciful plan when it came to punishing Sweden once this was over.
In the south, the Danish reinforcements had helped open opportunities to seize other Swedish territories in Pomerania, particularly the cities of Wismar and Stettin. However, Sweden had one last card in its deck: Holstein-Gottorp. The duchy had been neutral up to this point, but a fear of the possibility of Danish supremacy as well as the risk of losing the chance to eventually put a Gottorp on the Swedish throne scared the regent Christian August into declaring war against the Danish.
History would show that this was a terrible idea.
10,000 Holstein-Gottorp troops (including 5,000 well-trained soldiers) marched north on June 9, hoping to catch the Danish off guard and give the Swedish enough time to recuperate and focus against the Russian bear, only to be met with 20,000 Danish (many of whom had fought as volunteers against France), and 10,000 more men in a Saxon-Polish army sent to aid the Danish. Needless to say, the Danish and their allies (after momentarily being caught by surprise) completely clobbered the Holstein-Gottorp army, which by the end of 1713 was already being pushed back into its own territory while only succeeding in delaying the Danish attack on Swedish Bremen-Verden by a few months [2].
Near the end of the year on December 4, a Danish force of 9,000 soldiers manages to overwhelm the small (not to mention diseased) Swedish garrison defending Bremen, with Verden following 10 days after. When 1714 began, Sweden would only be fighting on its own territory.
Russia would welcome the new year via naval bombardment of Umea and Pitea, their recent naval victories and decreasing Swedish morale making the Russian captains more boisterous as the war progressed. Denmark chose to welcome it by finishing the seiges of Goteburg and Kalmar, taking thousands of Swedish soldiers prisoner whilst unleashing their hatred on the Swedish populace for decades of conflict. The Danish wanted the lands lost in years past and then some. With new Saxon and Polish reinforcements, the Danish force advanced in southern Sweden and met the Swedes at Jönköping on March 13th. The climactic battle of Jönköping saw 60,000 men of the Danish-Saxon-Polish alliance take on 35,000 Swedish in one of the bloodiest battles of the war (keep in mind this war involved Russia). The fighting lasted 2 weeks, but the Swedish force was eventually defeated and the city fell.
Both sides knew that Sweden's defeat was inevitable, but the Swedish generals and other nobles (the Empress herself was rapidly losing the already small bit of power she had at the start of her emergency-reign) hoped to at least muster enough men to fight their enemies to an honorable defeat. The Russians had other ideas.
In the spring and summer of 1714, a Russian fleet consisting of 132 galleys and several smaller boats, totaling 26,000 men, assaulted the Stockholm Archipelago. The Russian fleet pillaged along the coat of Uppland almost as far north as Gävle, and the coast of Södermanland as far south as Norrköping. The archipelago was severely devastated by the assaults. On several of the larger islands, almost all buildings were burnt down. The entire city of Trosa was burnt to the ground, save for the city church and bell tower. After receiving reinforcements, the Russian fleet attacked Stockholm on August 12, 1714. A grand total of 30,480 Russian soldiers attacked the city, and the Swedish garrison (which had its numbers reduced as a result of reinforcements desperately needed against Russia and Denmark) was overwhelmed. [3]
As the city's defenders were beaten (albeit at heavy cost to the Russian soldiers), the Russians began to pour across the city, both to find the Swedish monarchs and to exact their vengeance on the Swedish people. As some of the soldiers ran in the direction of the Stockholm Palace, most of them turned their hatred towards the civilians, killing and raping civilians by the thousands as houses were raided and burned, men were killed, and women were carried off by the more depraved Russian soldiers. It was a nightmare, and the streets of Stockholm were soon running red with blood. As for Empress Ulrika Eleonora, she was unable to escape Stockholm in time (she had delayed leaving as doing so would show the people of Stockholm that the war was lost) and was captured after the Russians killed her guards. She had stayed in her room, only for the Russian soldiers to smash it open before she could throw herself off it. With the Russian soldiers escorting her to prevent any escape and/or suicide attempt, Ulrika somberly stepped outside of her castle, where Field Marshal Mikhail Mikhailovich Golitsyn (who had led the attack on Stockholm) told her that it would be best if she surrendered. She quietly nodded, and after sending her few surviving advisers to tell the soldiers to stop fighting and to accept surrender, she began to quietly sob.
Within a week, fighting in both northern and southern Sweden would eventually cease. After the deaths of hundreds of thousands of people across northern Europe, the Great Northern War was over.
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[1] IOTL they did send tens of thousands of volunteers to help the Grand Alliance fight France in the War of Spanish Succession. This withdrawal of them before the war ends will have ramifications of slight to moderate scope on Europe after the WoSS ends. I say slight to moderate because it is only 1-2 years before the WoSS actually ended so much much it'll affect can't be too much.
[2] Not a major change from OTL, but ITTL the Danish didn't occupy Bremen-Verden in 1712 due to focusing more forces on the Swedish mainland.
[3] The Russian Pillage of Sweden happens 5 years earlier than IOTL, but unlike OTL, the attack on Stockholm succeeds.
So, there is my 3rd chapter, guys! The treaty in the next chapter is not going to be pretty for Sweden (a lot worse than IOTL), but on the maybe-bright side, developments will occur that will diverge from OTL that may change Russia and other countries for the better!