Wolfpack Prien
Prien's wolfpack is the name given in some sources to a formation of German U-boats that operated during the Battle of the Atlantic in World War II. It existed from 12 June to 17 June 1940. The group was named for Kapitänleutnant Günther Prien, commander of . Background Prior to the Second World War the German Navy's U-boat Arm, under its leader, Karl Donitz, developed its pack attack, a response to the convoy system that had defeated its war on commerce during the First World War. However, following the outbreak of hostilities its first attempts to use the tactic had been unsuccessful. Thereafter the UBW stuck to conventional patrols and solo attacks until diverted from the trade offensive to the invasion of Norway. With the end of the Norwegian campaign in May 1940, the UBW returned to attacking Britain's commerce. A further attempt to make the pack attack viable was made in June 1940 with the dispatch of Rosing's group of five U-boats, against a high-value convoy, US 3, off Cape Finisterre. Formation At the beginning of June, a second wave of U-boats was dispatched to operate against Allied shipping. Rohwer, the U-boat historian, lists seven U-boats (U-25, U-28, U-30,