 In 1821, the German lexicon "Das Gelehrte Teutschland" mentioned that he had been born in Metz, Lorraine.A 2003 investigation in the town archives in Metz has given further credence to the claim that Hacquet had been born in this town or its vicinity.The author hypothesised that Balthasar Hacquet was a son of a poor mother and an unknown father, baptised on 11 August 1736 as Jean.