Charles XII, after returning from the Ottoman Empire and resuming personal control of the war effort, had initiated two Norwegian Campaigns, starting in February 1716, to force Denmark–Norway into a separate peace treaty.

Furthermore, he had attempted to bar Great Britain access to the Baltic Sea.

In a search for allies, Charles XII had also negotiated with the British Jacobite party.

This had resulted in Great Britain declaring war on Sweden in 1717.

The Norwegian campaigns had been halted and the army withdrawn when Charles XII was shot dead while besieging Norwegian Fredriksten, a fortress in the city of Halden, on November 30, 1718 (OS).

He is succeeded by his sister, Ulrika Eleonora.