'Trondheim' was the German ground forces' movement, within 'Gelb', across the Albert Canal in Belgium against the fortress of Eben-Emael to relieve Oberleutnant Rudolf Witzig’s 'Granit' detachment of Hauptmann Walter Koch’s Fallschirmjäger-Sturmabteilung 'Koch', which had landed on the fortress in gliders and taken then it (9/10 May 1940).