Kyeser, a native of Eichstätt, was trained as a physician and lived at the court in Padua before he joined the crusade against the Turks which ended in disaster at the Battle of Nicopolis of 1396.
Kyeser, der stammede fra Eichstätt, blev uddannet læge i Padova inden han sluttede sig til korstoget mod tyrkerne, der sluttede som en katastrofe i Slaget ved Nikopolis i 1396.