Siegfried was a "wolfpack" of German U-boats that operated during the battle of the Atlantic in World War II.
Siegfried was formed in October 1943 to operate against the North Atlantic convoy routes and comprised 18 boats.
It consisted of seven boats from the disbanded group Schlieffen, plus eleven others from bases in France and Germany.
Siegfried was deployed to intercept east-bound convoys in mid-Atlantic, planning to attack while travelling towards the refuelling group and home bases in France.
None of these were successful, as the Allies were able to divert convoys around the patrol lines or steer through the gaps.