Trondheim (formerly Nidaros) is the third largest city in Norway and its main north-eastern port. It was one of the first cities occupied by the Germans during World War II.
British and French troops landed in Trondheim in mid-1939, just ahead of the invading Germans. However, their efforts to establish a defensive line there were seriously compromised because of their lack of armor, having only a few Bren-gun carriers, even though the Germans only had some Panzer IIs and captured CzechLT vz 35s that they had scrapped from other fronts at their disposal. The air was also dominated by the German Messerschmitts that flew from occupied Denmark and Oslo against whom the British Blackburn B-24 Skuas (the only planes the Allies could carry aboard ships, since there was too much distance to their nearest territory in the British Isles) or the Norwegian Fokkers, Capronis and Gladiators had little to do.
The Allied resistance was finally broken when the Kriegsmarine (despite heavy loses) and the Luftwaffe managed to cut the supply line between Trondheim and Britain. The remaining British, French and Norwegian forces retreated north in direction to Namsos.