Research into military use of long-range rockets began when the graduate studies of Wernher von Braun attracted the attention of the German Army. A series of prototypes culminated in the A-4, which went to war as the . Beginning in September 1944, over 3,000 were launched by the German Wehrmacht against Allied targets, first London and later Antwerp and Liège. According to a 2011 BBC documentary, the attacks from resulted in the deaths of an estimated 9,000 civilians and military personnel, and a further 12,000 forced laborers and concentration camp prisoners died as a result of their forced participation in the production of the weapons.