Bergen was the first Norwegian port to be established as a U-boat base.

By securing access to Norwegian ports, the Germans could more easily obtain the supply of iron ore they needed for their war effort.

U-221 departed Kristiansand on 3 September 1942 having moved to the Norwegian port a day earlier.

The objective of the force was the northern Norwegian port of Bodø.

The problem could only be rectified in Bergen, which involved a perilous voyage on the surface to the Norwegian port.

Pegram's significance comes from three daring voyages into Norwegian ports with the threat of German air attack.

Participating units were divided into five groups, which were to occupy six of the main Norwegian ports.

By 11:00, the battleships had destroyed their targets and headed back to their Norwegian ports.

The idea was to seize the main Norwegian ports.

The patrol itself commenced with the boat's departure from the Norwegian port on 17 July 1942.