Hirschfeld, the son of a Mecklenburg merchant, was largely educated and trained abroad, in South America, Spain, London, and Paris. On 23 October 1935, he joined the mountain infantry regiment 98 in Kempten.[citation needed] In September 1943, as a colonel in the 1st Mountain Division, he played a major role in the massacre of the Acqui Division, the murder of 5,155 Italian prisoners of war of the 33 Mountain Infantry Division Acqui in Cephalonia.[1]