The Battles of Usedom were fought on 21–27 April and 31 July–22 August 1715, between Swedish and Prussian, Saxon and Danish forces. In 1711, the Great Northern War spread to Germany as the anti-Swedish coalition invaded Swedish Pomerania, capturing the islands of Wolin and Usedom, as well as Stettin (Szczecin) in 1713. In pursuit of allies, Sweden's enemies offered neutral Prussia to hold guardianship over the conquests, an offer which the ambitious Frederick William I accepted. Charles XII of Sweden launched a preemptive strike to retake Usedom on 21 April 1715, to prevent the allies from utilising its waterways against Stralsund. All Prussians troops were forcibly removed from the island by the 27th, resulting in a Prussian declaration of war. In July, Prussia, Denmark–Norway, and Saxony blockaded Stralsund.
An invasion of Usedom was deemed necessary to have equipment shipped to the blockading army, and to cut Stralsund off from Sweden proper by capturing Rügen. A Prussian–Saxon army crossed the Swine (Świna) strait from Wolin on 31 July 1715, compelling Charles to withdraw to the last strong-point on the island, Peenemünde Sconce. A small Swedish rearguard that was covering the retreat was cut down. Charles quit the sconce the next day and instructed its commander to fight to the end. It was taken by storm on 22 August, with the allies suffering heavy losses and the entire garrison being killed or captured.
The loss of Usedom weakened the Swedish defence of the Greifswald bay, which protected the island of Rügen from an allied invasion. A Danish fleet forced an entry into the bay on 25 September. A formal siege of Stralsund began on 19 October, with the start of trench-digging and artillery bombardment. On 15 November, the allies landed on Rügen as the Swedes were occupied in the front. Charles counter-attacked but was repulsed, resulting in the loss of the island and the inevitable fall of Stralsund. Charles escaped the encirclement on 22 December, and Stralsund surrendered the next day. The city was returned to Sweden by the treaties of Stockholm and Frederiksborg, but Usedom, Wolin and Stettin were ceded to Prussia.
Background
Invasion of Swedish Pomerania
During his Ottoman exile following the defeat at Poltava, Charles XII planned to use Swedish Pomerania as a staging point for new offensives into the Polish–Lithuanian Commonwealth and Russia in conjunction with the Ottomans. Wishing to save Sweden's German dominions, however, Arvid Horn and the Swedish council signed The Hague agreement of 1710 which declared them neutral, thwarting any plans of a Swedish offensive and alliance with the Ottomans. Consequentially, Charles rejected the neutrality-agreement and demoted or dismissed several civilian and military key figures whom he deemed too defensively minded or incompetent.
In September 1711, Frederick IV with 22,000 Danes, and Augustus II with 20,000 Poles, Saxons and Russians invaded Swedish Pomerania from the west and southeast, respectively. Their numbers compelled the Swedish commander Carl Gustaf Dücker to concentrate his 11,000-man army at Stralsund and Stettin (Szczecin), leaving most of Pomerania defenceless. The first allied Siege of Stralsund ended in failure as most Danes withdrew from Pomerania in January 1712, having lost up to a third of their army. But they still held the city under blockade. 20,000 more Russians arrived in July. Peter I and Augustus tried but failed to take the Rügen island in September. Stralsund and Stettin were given temporary respite later that month when an army under Magnus Stenbock was shipped over from Sweden. Following a brilliant victory at Gadebusch, Stenbock capitulated at Tönning in May 1713.
Rising Prussian–Swedish tensions
Stettin was captured by the allies on 6 October 1713 and its commander, Johan August Meijerfeldt, accepted the terms of the Schwedt treaty; neutral Holstein-Gottorp and Prussia would administrate Stettin until a conclusive ruling-agreement was reached, with Sweden covering the 400,000 thalers that Prussia had paid Russia for the city. The treaty was, nevertheless, deemed illegal by Charles who futilely demanded Frederick William I to return the city. Tensions rose in 1714, with the Prussian acquirement of the Swedish ferry-town of Wolgast and the island of Usedom by Sweden's enemies. The allies withdrew from Stralsund in October, a month prior to Charles arrival at the city after several years in exile.
Recognising neither Usedom nor Wolgast as part of the Schwedt treaty, Charles sent a Swedish detachment to retake the latter on 23 February 1715. The Prussian garrison was forcibly removed and shipped over to Usedom. The Swedish king was well-aware of the ongoing negotiations between Prussia and his enemies, and Frederick William's ambitions to permanently keep the occupied territory. As further diplomacy stalled, and war against Prussia seemed inevitable, he decided on a preemptive strike against Usedom before the Prussians consolidated their hold of the island. Usedom was crucial in the defence of Stralsund, as it protected vital waterways leading to the city. Some 3,000 men were assembled for the task. Lieutenant colonel von Jeetze commanded more than 300 Prussians on the island.
Swedish reconquest of Usedom
Plan of attack
Charles XII planned for 300–400 men to land on the eastern side of Peenemünde and dislodge any Prussians along the main road over Pudagla to the town of Usedom, to deny reinforcements from that direction. Additional troops would be shipped over along the Peene strait near Wolgast, to enclose Wolgaster Fähre (opposite Wolgast) and the Peenemünde sconce, before advancing upon Swine Sconce further east. The latter had been partially destroyed in a Swedish raid in 1712. He estimated that 14 days would be enough to starve them out. Violence would only be used if necessary – the two nations were not yet at war with each other.
Preemptive strike
Accordingly, a Swedish fleet, consisting of 500 men onboard three frigates and seven or eight smaller ships under vice admiral Mikael Henck, sailed to Peenemünde where the small force landed on Easter of 21 April. Some 100 Prussians standing as reserve within the municipality were captured in the Swedish advance. Meanwhile, the fleet proceeded along the Peene strait to Wolgast and shipped over the land forces under Dücker the following day, which had marched from Stralsund. The Swedish activity was observed by Rohr, the Prussian captain at Peenemünde Sconce, who notified major general Schwendi at Wolin. At Wolgaster Fähre, the Swedes initially ignored the 19-man strong redoubt but captured the captain and 76 men lying outside. Rohr and his garrison of 123 men were after some time also enclosed.
The Swedes proceeded further onto the island towards the last strong-point Swine Sconce, near today's Świnoujście, which guarded the mouth of the Swine (Świna) strait and crossing over to Wolin. The garrison's nominal strength was 40 men. The fleet simultaneously sailed into the Swine in support. When Swedish infantry arrived at the sconce on 23 April, its commander sub-lieutenant von Plotho ignored their demands to surrender and opened fire. Charles then commenced a storm, which cost five or six killed and 20 wounded all together, including mortally wounded von Plotho. Three 3-pounder guns were also captured. The Swedish conquest of the island was completed by the 27th when Rohr surrendered Peenemünde Sconce due to inadequate provisions.
The Prussians made no attempts to reinforce Usedom during the action; having received reports from general Schwendi, 500 infantry and some cavalry arrived at Wolin from Stettin to block a continued Swedish advance. This force gradually increased to nine battalions and ten squadrons as the Prussians erroneously assumed Charles would continue his offensive into Poland. Since Sweden and Prussia were not formally at war, most captured Prussians were sent over to their comrades at Wolin with all their firearms and equipment. The ones captured at Wolgaster Fähre were instead escorted to Anklam. The conquest of Usedom made the Swedes masters over the Stettin lagoon and the imminent waterways, the Swine and Peene straits.
Intermediate phase
Prussian declaration of war
In response, Frederick William I expelled the Swedish ambassador in Berlin and declared war on 1 May 1715. The Holstein-Gottorp troops in Stettin, whom Frederick William viewed as Swedish auxiliaries, were imprisoned. The Prussian king assembled his army at Stettin, with defences stretching along the Peene river, whilst awaiting the results of allied negotiations before going on the offensive. Eight small Swedish privateers on the lagoon and waterways began harassing the Prussians, which would prevent them from transporting artillery via Anklam and the Greifswald harbour to Stralsund.
Skirmishes began on 16 June, when Prussian troops crossed the Peene between Loitz and Demmin and overwhelmed a small Swedish outpost of 30 men. Charles arrived at Loitz the next day and ordered lieutenant colonel Johan Segersten (later Stenflycht) to retaliate. On 18 June, with 200 cavalry and 200 infantry, he drove the Prussians back over the river. The redoubts at Jarmen, Gützkow and Stolpe were also destroyed by Segersten who continued south-east along the Peene before heading back with 100 POWs. Charles got separated from his troops in the offensive and was nearly captured. With 100 cavalry-reinforcements, Segersten once again crossed the river with 300 cavalry and advanced towards Neubrandenburg, capturing 130 Prussians. In total, 200–270 Prussians were made POWs at the Peene, of whom 161 were exchanged with troops imprisoned at Stettin.
Stralsund offensive
Negotiations finalised by the month's end and the offensive began. The allies had 50,000 men, against 12,000–13,000 Swedes. The Danes broke into Swedish Pomerania on 8 July. The Prussian–Saxon army crossed the Peene the next day, following a small skirmish. The Swedes offered only sporadic resistance, and abandoned Greifswald in their retreat. The allies reached Stralsund on the 14th, and began the construction of a contravallation line two days later. But to capture the city, they first had to cut it off from Sweden proper by taking the Rügen island, which required naval supremacy over the Greifswald bay. With the approach of the winter freeze, time was of the essence.
After some fighting, which got Christen Sehested's Danish fleet trapped by the Stralsund fleet in the southeastern part of the bay, this was deemed impossible so long as Sweden controlled the Usedom and Ruden islands; an invasion of Usedom was necessary to utilise its vital waterways for Prussian artillery transports to Stralsund, and for Sehested's fleet to collect fresh water, which the Swedish cavalry effectively prevented. Hence, on 24 July, Frederick William ordered the invasion. To enable troop shipments over the Peene strait to Usedom, the Prussians first captured Wolgast and its castle on 27–29 July after some resistance.
Allied invasion of Usedom
At dawn on 31 July 1715, a Prussian–Saxon force of 2,000 infantry and 800 cavalry under general Georg von Arnim began crossing the Swine from Wolin. The main column under von Arnim crossed just north of Swine Sconce, and a second column under Saxon major Frederick Louis of Württemberg-Winnental further south. On Usedom, Swedish general Christian Grothusen commanded between 600 and 800 men. He prepared to receive the allies above Swine Sconce, opposite the main crossing, with 400 infantry and some cavalry, or 600 men in total. When Charles arrived and saw Grothusen's vulnerable position, he ordered a withdrawal; this was also done to avoid being cut off in the rear in case of an allied attack over Wolgast. 13 dragoons remained to observe the enemy while the rest of the Swedish force withdrew.
Swedish retreat