 The only time the fortress has been in battle was against a British fleet force, led by in 1807 during the Napoleonic Wars.One of the very few remaining larger warships under Danish-Norwegian command was the ship of the line HDMS "Prinds Christian Frederik" with 70 cannons that was in the eastern harbor of Kristiansand.Captain Stopford on board HMS "Spencer" ordered to sail toward the city and announced in a letter that he wanted to take over the HDMS "Prinds Christian Fredrik", and threatened to open fire on the city if the ship were not disclosed.