In 1718 Charles once more invaded Norway. With a main force of 40,000 men, he again laid siege to the fortress of Fredriksten overlooking the town of Fredrikshald. Charles was shot in the head and killed during the siege, while he was inspecting trenches. The invasion was abandoned, and Charles' body was returned to Sweden. A second force, under Carl Gustaf Armfeldt, marched against Trondheim with 10,000 men but was forced to retreat. In the march that ensued, many of the 5,800 remaining men perished in a severe winter storm.