Operation Wilfred was a British and French naval operation during the Second World War that involved the mining of the channels between Norway and its offshore islands to prevent the transport of Swedish iron ore through neutral Norwegian waters. The Allies assumed that Wilfred would provoke German retaliation in Norway and prepared Plan R4 to occupy Narvik, Stavanger, Bergen and Trondheim. On 8 April 1940, the operation was partly carried out but was overtaken by events, when the Germans began Operation Weserübung on 9 April, the invasion of Norway and Denmark, which began the Norwegian Campaign.
