The Attack on Marstrand was a successful Dano-Norwegian siege of Marstrand and Carlsten fortress which took place between July 10–16, 1719 during the final parts of the Great Northern War. The Danes had subjected the Swedish city of Gothenburg to a blockade during the spring of 1719 to combat the Swedish privateers. After a Dano-Norwegian assault on northern Bohuslän, ships under the command of Peder Tordenskjold had also assaulted the Marstrand harbor and the immobile naval ships in the Swedish Gothenburg Fleet. After these ships had been sunk, the Danes mounted their final assault on Carlsten fortress, whose garrison surrendered swiftly, partly because of psychological warfare. The commander of the fortress, Colonel Henrich Danckwardt, was later sentenced to death by a Swedish court mart