There were a number of members of the Leyser family who achieved notability during this period, but Michael would be unusual among them in not becoming a theologian.
His mother, Sabine, was the daughter of Nikolaus Volckmar (1573-1602), a book dealer who at one stage served as the major of Leipzig.
He then switched to Medicine, studying under Thomas Bartholin at Copenhagen, where he mastered the full range of knowledge and experience on the subject of Anatomy.
Hoc est: Methodus brecis, facilis ac perspicua artificose et compendiose humana incidendi cadavera"'.
The illness that killed him is identified as a " "Febris maligna", a "cold fever" probably caused by Typhus or Plague.