But the fortress held out and was not surrendered to the Swedes until after the Convention of Moss .
During the Swedish campaign against Norway in 1814 , Fredriksten fortress came under siege , and suffered under heavy bombardment .
The fortress held out and was not surrendered to the Swedes until after the Convention of Moss .
During the Swedish campaign against Norway in 1814 , Fredriksten fortress came under siege , and suffered under heavy bombardment .