Dresden was widely considered a city of little war-related industrial or strategic importance, though, after the fact, in his memoirs Winston Churchill described it as a “centre of communications of Germany’s Eastern Front.” Dresden itself was most noted as a cultural centre, with noted architecture in the Zwinger Palace, the Dresden State Opera House and its historic cathedral (the Frauenkirche) and other churches. It was also called “Elbflorenz”, i.e. Florence of the Elbe, due to its stunning beauty. It has been claimed that the bombing was at the request of the Soviet Union, to attack a German armoured division in transit through the city. However, RAF briefing notes indicate that one of the motives was to show “the Russians when they arrive, what Bomber Command can do” (that is, to intimidate the Soviets).
At the time, the city was crammed full of refugees fleeing from the advancing Red Army. Dresden, having been spared from previous attacks, was considered to be very safe. Bomber Command was ordered to attack Berlin, Dresden, Leipzig and other east German cities to “cause confusion in the evacuation from the east” and “hamper the movements of troops from the west”. This directive led to the raid on Dresden and marked the erosion of one last moral restriction in the bombing war: the term “evacuation from the east” did not refer to retreating troops but to the civilian refugees fleeing from the advancing Soviet troops. Although these refugees clearly did not contribute to the German war effort, they were considered legitimate targets simply because the chaos caused by attacks on them might obstruct German troop reinforcements to the Eastern Front. There are eyewitness reports that civilians fleeing the firestorm engulfing Dresden in February 1945 were strafed by British and American aircraft.
https://www.youtube.com/playlist?p=PL74C99B32700798F6
