In February, 1716, Charles XII., from Bohuslæn and Vermland, made an invasion into Norway, penetrating over the Glom River to Christiania. He captured the capital, where he held his headquarters for several weeks, but was not able to take the fortress of Akershus, which, with its artillery, commanded the city. The Swedish army, 10,000 strong, suffered a great deal from want of provisions and through a guerilla war, skilfully conducted by the Norwegians. Charles was in danger of being surrounded by the enemy, and with difficulty retreated to Sweden, over the Strait of Svinesund. The dangers were increased by the Norwegian naval hero, Peter Tordenskiold, who, with some Danish ships under his command, had destroyed a flotilla of Swedish transport vessels. An invasion into Scania by Denmark and her allies was planned for the summer, but did not materialize. King Charles took up his headquarters at Lund. The war offered no aspect of interest during the year 1717, except some unsuccessful attempts made by Tordenskiold to capture the towns of Strœmstad and Gothenburg. Charles prepared another attack on Norway, and, by draining the last resources of his country, managed to equip an army of 60,000 men. In August, 1718, a smaller army, under the command of Charles Gustavus Armfelt, was sent through Jemtland over the mountains into the diocese of Drontheim. King Charles, with an army of 30,000 men, invaded Norway from Bohuslæn, Dal and Vermland, and took in possession the country east of the Glom River. Within a few days the king laid siege to the fortress of Fredericsten, close by the town of Fredricshall. November 27th the fort of Gyldenlœve was captured, and the Swedes moved their trenches ever closer to the fortress, which seemed doomed to surrender. In the evening of November 30th the king was seen in one of the trenches watching the work of his soldiers, and leaning against the rampart. He remained there a long time, not heeding the appeals of his officers, who grew uneasy on account of the apparent danger to his person. Suddenly his head sank down on his breast. A bullet from the fortress had reached him, penetrating his temples and causing instant death. He met death in the manner he most desired it, although not while engaged in battle.