'Basis Nord' was the German maritime undertaking in which the blockade-running ships Bremen (a 51,656-ton liner) and New York departed US eastern seaboard ports on 6 and 8 September 1939 respectively, met the 16,732-ton St Louis on 13 September and then steamed in company to reach Germany’s 'north base' at Murmansk in the northern USSR on 18 September (6/18 September 1939).

On this last date, fewer than four weeks after the signature of the 'Molotov-Ribbentrop Pact' (Treaty of Non-Aggression between Germany and the USSR), there were already 18 German merchant vessels at Murmansk awaiting the opportunity to reach German ports.