Siege of Fredriksten The Siege of Fredriksten was a siege of the Norwegian fortress of Fredriksten in the city of Halden by Charles XII of Sweden . While inspecting his troops ' lines , Charles XII was killed by a projectile that shot into the left side of his head and out of the right . The Swedes broke the siege off , and the Norwegians kept the fortress . Background . King Charles XII of Sweden made several campaigns into the city during the Great Northern War during his campaign to capture Denmark – Norway . At the close of the Great Northern War , the Norwegian Army had been weakened in early 1716 by withdrawal of 5000 of the best troops to Denmark . When rumors reached Christiania that Charles XII was preparing to invade , all remaining troops in Østerdal and Gudbrandsdal were ordered to the border at Halden and Fredrikstad . The Norwegians expected the Swedes to invade at Kongsvinger , Basmo and / or Halden . It was at Basmo where Charles XII struck , crossing the border March 8 , 1716 . The Norwegian scorched earth policy and guerrilla raid interdiction of supply chains by the residents of Bohuslen deprived Charles of supplies , while the fortresses still held by the Norwegians behind his lines threatened his supply chain and his retreat if seriously weakened in combat . Charles took Christiania ( now Oslo ) , but without heavy siege artillery , was unable to take Akershus . After a brief occupation , Charles retraced his steps to the Norwegian fortresses in southeastern Norway with the objective of capturing Frederiksten . This would remove the threat at his back , and the fortifications could serve as the base for a renewed offensive later that year . Capturing the harbours at the mouth of the Glomma river would also allow him to land the necessary provisions for a successful siege of Akershus . Charles ' troops attempted to take Frederiksten by storm on July 4 . His troops took the town after fierce fighting , but the citizens set fire to their own houses , forcing Charles , unable to take the fortress , to retreat and await the arrival of heavy siege guns . Unfortunately for the invading army the entire Swedish transport fleet was captured or destroyed by the Norwegian naval hero Tordenskjold at the Battle of Dynekilen in Bohuslen . Running low on supplies , Charles retreated hastily across the Svinesund and burned the bridges behind him . By July 12 , 1716 all Swedish troops had been withdrawn from the area around Fredriksten . Siege of 1718 . Charles came again to besiege the fortress in autumn of 1718 with 40 , 000 men . He did this intending to first capture Halden to be able to sustain a siege of Akershus . By first taking the border areas , Charles wished to avoid a repeat of the fiasco he had suffered two years before . The 1 , 400 strong garrison of Frederiksten fought ferociously to hold back the invasion , but suffered a severe setback when , on December 8 the forward fortification Fort Gyldenløve fell . Encouraged by their very hard - fought success the Swedish army intensified their efforts against the main fort . The Swedish trenches had almost reached the main fortification walls when on the evening of December 11 ( Swedish calendar : November 30 ) , 1718 , a projectile struck and killed Charles XII while he inspected the work . The death of the king effectively ended the attack on Fredriksten and the invasion was called off , leading to the conclusion of the war . A memorial is located in the park named in his memory where the Swedish king fell , just in front of the fortress . Expedition by Carl Gustaf Armfeldt . Carl Gustaf Armfeldt tried to take the city of Trondheim via Fredriksten while the siege was still going on . Poorly equipped , Armfelt pulled out after the king fell at Fredriksten . The ensuing disaster that struck his army is known as the Carolean Death March . On New Year ' s Eve 1718 he arrived at Norwegian Tydal , with 80 kilometers to the closest Swedish village in Jämtland . When the troops had marched 10 kilometers from Tydalen , a severe blizzard struck from the northwest . The bitter cold killed the guide on the very first day , and the army scatted blindly in the mountains ( Sylan mountain range ) . On the following nights hundreds more perished . Of the over 5 , 000 men who left Tydalen , only 870 were found alive on arrival at Duved , mostly hardened Finnish veteran s . Aftermath . The siege in 1718 was the last invasion of Norway in the Great Northern War . The war ended on the end of the siege of Fredricksten and the death of Charles XII .