Opposing the invasion were the partially mobilized Norwegian military, and an allied expeditionary force composed of British, French, and Free Polish formations.
On 1 March 1940, the German 21st Army Corps was renamed Group XXI and placed in charge of the invasion of Norway.
It was led by the commanding officer of the XXI Korps, General der Infanterie Nikolaus von Falkenhorst.
Patron-Flotilla – Kapitänleutnant Dr. Walther Fischer Objectives Middelfart and Belt Bridge Warship Group Nine – Kapitän zur See Helmut Leissner, F.d.V.O Objectives Esbjerg and Nordby Warship Group Ten – Kapitän zur See and Kommodore Friedrich Ruge F.d.M.
Minesweeper Flotilla – Kapitänleutnant Hagen Küster Mine Sweeper Covering Group Laying minefields to the Skagerrak to protect the German resupply route to southern Norway.
Commanded by Major-General Bernard Charles Tolver Paget, this force landed at Åndalsnes starting 18 April.
Commanded by Major-General Pierse Joseph Mackesy, this force landed at Harstad, north of Narvik, between 15 April and 5 May.