The battles at Göta älv were a series of battles and sieges which took place in and around the Gothenburg area between 1717 and 1719, between the Swedish Empire and Denmark–Norway, during the Great Northern War.
When Charles XII was forced to halt his assault on southern Norway in 1716, Dano-Norwegian troops, under the command of the young commander Peter Tordenskjold, attempted to blockade Gothenburg and assault its newly constructed naval base; Nya Varvet (New Shipyard) in the spring of 1717, but was unsuccessful. Tordenskold also attempted an assault on Strömstad, also without success. The attacks resulted in the Swedes rebasing their Gothenburg Squadron to Marstrand, some smaller vessels were rebased to Strömstad.
Following Charles XII's renewed assault on Norway in the autumn of 1718, as well as the breakdown of the 1719 peace negotiations, Denmark–Norway launched yet another assault targeting Bohuslän. The goal for the Dano-Norwegian forces was to achieve a quick end of the war with a resulting territorial loss for Sweden, but also to halt the Swedes' privateering operations which were taking a toll on Denmark–Norway. Strömstad was quickly conquered by early July 1719, and the strong Carlsten Fortress at Marstrand was conquered by Tordenskjold, partly thanks to psychological warfare. During the battles in and around Marstrand, large parts of the Gothenburg Squadron were sunk by friendly forces in order to prevent its vessels from falling under enemy control. A subsequent Dano-Norwegian assault against the New Älvsborg fortress in the riverhead of Gothenburg's inlet port was countered by the Swedes. Just before hostilities would calm down in the autumn of 1719, Tordenskjold launched yet another assault on Nya Varvet, this time with fewer troops but ultimately resulting in a more successful operation than the one that preceded it.
Background
Following the Swedish defeat in the Battle of Poltava in June 1709, Denmark–Norway declared war on Sweden on 8 August (O.S) that same year. Subsequent Russian attacks resulted in the seizure of Swedish defense structures across all of the Baltic region as well as parts of Finland. The new Russian naval base Kronstadt as well as other newly conquered Baltic ports became bases for Russian vessels.
This drastically changed the situation for the Swedish Navy, as they had to focus more on the growing Russian Navy, compared to before, when the Swedes had concentrated their efforts on the Danes in the southern Baltic Sea and Øresund. The vital objective was to prevent the Danes and Russians from coordinating and combining their naval power. This situation was a major strain on Swedish resources and it made the defense of their western waters from the Dano-Norwegian fleet especially difficult. The Gothenburg area was considered a relatively low priority, despite the fact that the city's trade significance was growing.
The construction of a new, deeper naval base, Nya Varvet (New Shipyard), had begun in 1700 at the river entrance of Lilla Billingen, which was supposed to replace the existing Gamla Varvet (Old Shipyard), at what is today Stigberget. In addition to Gothenburg city fortress, the coastal fortress New Älvsborg in the river entrance of Göta älv, as well as Carlsten in Marstrand had all been expanded during the last decades.
In 1704 it was decided that forced naval conscription was to be performed in the former Danish provinces (Scania, Bohuslän and Halland, among others) which were now part of southern Sweden. This meant that the part of the population that were fit for naval service were obliged to serve the navy during times of war, in exchange for some benefits. The local enthusiasm, however, was low, and many seamen fit for service instead sought service in the Danish and Norwegian navies. By spring 1715, 72 of the 140 naval officers that were conscripted in Gothenburg were ordered to Stockholm and the navy in the Baltic Sea.
In order to compensate for the Swedish navy's diminished resources, letters of marque were issued, which authorized crews of armed, privately owned Swedish vessels to seize vessels belonging to nations that Sweden were at war with, and to an extent, sell their cargo. The crown received a 10 percent cut on these sales. Starting in 1710, privateering companies were being set up as a result. In 1711, the Crown allowed loyal privateers to borrow weapons and munitions from the government's Gothenburg storages. Admirals complained that privateers were using conscripted sailors during their operations that were supposed to be serving in the Navy.
Swedish privateering operations expanded further in 1715 when foreign navy captains were authorized to receive letters of marque and to operate under Swedish flag. It was also no longer mandatory to pay a cut of the cargo value to the Swedish crown. By 1715, a total of 25 Swedish privateers were conducting active operations in the Western Sea, which disrupted Dano-Norwegian trading routes severely. The largest privateering operation was led by Lars Gathe of Onsala. He was named Gathenhielm and Commander by Charles XII so he could not only command his privateering operation, but also the entire Swedish privateering fleet on the west coast.
Charles XII's Norwegian Campaign of 1716
In February, a smaller Swedish force composed of men from Värmland, Dalsland and Svinesund, marched into Norway with the intention of conquering Akershus fortress in Christiania, thereby forcing Denmark to make peace. After passing by the fortress town of Fredrikstad as well as Fredriksten fortress, near present-day Halden, Charles XII was able to march in to the undefended Christiania by 11 March, whilst under persistent fire from Akershus fortress. After a failed storming attempt, Charles XII realized that he needed access to more powerful siege artillery. Repeated attempts to defeat the Norwegian forces around Swedish-occupied Christiania failed because of General von Lützow's skilled defensive tactics and by him avoiding as many battles as possible, since he was aware that his relatively untrained army couldn't compare to the seasoned Swedish Caroleans. Additionally, the coming thaw meant that Danish reinforcements could start arriving by ship. The rough Norwegian terrain, combined with the lack of supplies and the active resistance of the local civilians forced the Swedish Army to retreat south.
A major cause to the Swedish defeat during the campaign was the inability to compete with the Danes on the sea. The commander of the Gothenburg Squadron, Vice admiral Axel Lewenhaupt, had only managed to put one frigate, the Älvsborg (46 cannons) to sea, by letting privateers borrow it for 20 000 daler. This, of course, did not prevent Danish vessels from supplying the Norwegians with soldiers and supplies. The Danish General Staff credited the retaking of Christiania to their fleet. In Gothenburg, Vice-Admiral Lewenhaupt had under rough circumstances managed to put together a transport fleet consisting of 24 vessels loaded with siege cannons, ammunition and other supplies. The fleet was escorted by six galleys and an armed barge. It moved slowly north along the coast under the command of schoutbynacht Olof Knape. By the end of April, it entered Dynekilen, a fjord between Strömstad and Svinesund. Additional transport ships arrived during the following months.
Battle of Dynekilen
During the night of 28 June, Norwegian Commander Peder Tordenskjold initiated one of the most daring and most widely renowned naval battles in Nordic history. By sailing directly into the approximately 5 kilometer long and narrow fjord with frigates, galleys and armed barges, the Swedes were taken by surprise. The Dano-Norwegian superior number of cannons meant that the entire Swedish transport fleet was either sunk or captured after five hours of combat.
Without any usable siege artillery, and with a high risk of being cut off, Charles XII ordered a full retreat of the Swedish Army on 29 June. His soldiers managed to cross over to the Swedish side of the Idefjord, before Tordenskjold could destroy the bridge at Svinesund. The 25-year old Tordenskjold was promoted to captain, and in November he was designated Chief of the Norwegian Navy. The Swedish captain Strömstierna managed to reach land from the galley Wrede, and despite his defeat, he was promoted to vice admiral by Charles XII.
By early 1717 the Danes were still worrying that Charles XII would resume his invasion of Norway. Swedish privateers based in Gothenburg were still persistent in their harassing of Dano-Norwegian trade. Tordenskjold therefore prepared an assault on the Gothenburg Squadron and as much as possible on the Gothenburg-based privateering squadron at Göta älv. The moment of surprise would gain significance, as it did at Dynekilen. There were however no plans on attacking the New Älvsborg fortress or the Gothenburg city fortress. By February, Danish vessels had started blockading the river mouth of Göta älv.
1717 Attack on Nya Varvet
In the morning of 2 May 1717, a Dano-Norwegian naval force anchored in the Gothenburg archipelago with the purpose of conducting a night raid against Swedish harbors and dockyards in the city, but their moment of surprise was lost from the beginning. This happened because of disagreements between the Dano-Norwegian commanders which ultimately resulted in one of the necessary barges; the Arca Noæ not arriving on time. The Danes under the command of Tordenskjold, still managed to maneuver past New Älvsborg fortress with barges, galleys and slopes containing around 100 cannons and 1800 soldiers, during the night between 2 and 3 May.
As a result of the Danish disorder before the battle, the Swedes could spare a few additional hours to see over their defenses. The defense of Gothenburg was formally led by Carl Gustaf Mörner, the governor of Gothenburg and Bohus County, but was in practice being led by Olof Strömstierna. Frederick I, a future successor to the Swedish throne, was because of co-incidence in Gothenburg at the time and took part in the fighting.
Two of the Gothenburg Squadron's frigates, the Fredericus and the Halmstad had been leased to the Gathenhielm privateers. The Halmstad was equipped, but undermanned. These two frigates as well as an additional two from Nya Varvet, formed a blockade in Göta älv between Nya Varvet and Rya Nabbe. Strömstierna supplied the vessels with barricades so as to prevent the Danes from boarding them. Additionally, New Älvsborg fortress had been reinforced with a crew of 400 soldiers and 90 cannons. The two cannon batteries Lilla Billingen and Rya Nabbe, with 12 heavy cannons each had been manned with infantry from the Saxon Infantry Regiment led by Colonel G.D Zengerlein. In addition, the Småland Regiment as well as an elite unit, the Grenadier Battalion led by Johan Clausen, which composed of handpicked grenadiers from different units, were assigned to man the forts. In total, there were around 1000 Swedish soldiers and 200 cannons at the rivermouth of Göta älv.
At roughly 8 in the morning, the Danes were forced to retreat, due to them not being able to breach the Swedish defenses. The Danish force sailed with an east-bearing wind out of Göta älv, with a slightly reduced fleet. Two galleys were left behind by the Danes and captured by the Swedes. The raid resulted in 52 casualties and 79 badly injured for the Danes. 40 were mildly injured and could keep working. Tordenskjold's superiors questioned his judgement due to his order to go ahead with the raid despite the circumstances. In the evening of 15 May, the blockade of Gothenburg was lifted and Tordenskjold's squadron started its sail towards Norway.
War in Northern Bohuslän
Following their victory against Tordenskjold in May 1717, the Swedish military deemed that Strömstad was in a vulnerable position and that it required reinforcement. Captain Nils Gyllenschruf succeeded in transporting soldiers, cannons, ammunition and grain from Gothenburg to Strömstad by 14 June. The troops were part of the Halland Regiment and the previously mentioned Grenadier Battalion. The Västerbotten Regiment was also ordered to Strömstad. A major fortification project ensued, and by 29 June, Major General Johan Giertta, who was responsible for the defense of the border with Norway, could report that two cannon batteries were operational and the remaining two were near completion.
On July 8, Tordenskjold assaulted Strömstad with a squadron, and following heavy firing upon the city, an attempt was made to land soldiers escorted by galleys. The assault failed when the Swedish counterattack couldn't be stopped despite firing against them by Danish ships of the line and barges. A number of attacking galleys got stuck on rocks and were stranded. At 15 to 20 meters distance, Swedish grenadiers were able to hit with devastating musket salvos. The Danish casualties numbered 96 in addition to their 246 injured. Among the injured was Tordenskjold himself who was carried back to the ship of the line Laaland, bleeding and barely conscious. He was promptly replaced by the more careful Schoutbynacht Andreas Rosenpalm.
Charles XII visited Strömstad and Gothenburg in September 1717. He decided that the Gothenburg Squadron was to be moved, and that its larger vessels, the frigates, were to be placed in the more strongly fortified Marstrand. The lesser vessels were to be based in Strömstad. Missing dockyards and storage facilities were to be constructed as soon as possible, by order of the King.