On 5th May 1941 Hitler started Operation Rheinübung to sever Britain's lifeline which consisted of merchant ships bringing vital supplies such as food and raw materials. If this lifeline was cut Britain would be forced to either sue for peace, negotiate an armistice or leave the British Isles. The goal of Rheinübung was to break into the Atlantic ocean and attack allied merchant ships transporting essential goods. German Naval Command (OKM) established a network of tankers and supply ships around the area "Bismarck" and "Prinz Eugen" sailed. Britain knew Nazi Germany was going to attack these supply lines and stationed multiple battlecruisers, aircraft carriers, and battleships.