Competing since 2010, Gassmann is a top-ranked international longsword competitor who has medaled on both sides of the Atlantic. His competitive highlights include winning Gold at SOCAL (2021), Bronze at the HEMA invitational tournament of the European Games in Minsk (2019), Gold at Fightcamp (2018), and Gold at the Arnold Schwarzenegger Open (2016).

He is also a researcher and writer, publishing peer-reviewed articles on both longsword (1) and medieval cavalry (2, 3). In addition to longsword, Gassmann has studied and practiced Rossfechten (i.e., mounted fencing) since 2014. Combining those expertise, Gassmann currently works in the film industry, applying his knowledge of HEMA to screen combat and stunts (4).

As an Instructor, he blends modern sport science and historical training methods to develop physical intuition, improving both body mechanics and decision-making.

1. Gassmann, J., Gassmann J., and Coultre D. (2016). Fighting with the Longsword: Modern-day HEMA Practices. Acta Periodica Duellatorum, 5(2), 115-133. https://doi.org/10.1515/apd-2017-0011

2. Gassmann, J. (2014). Thoughts on the Role of Cavalry in Medieval Warfare. Acta Periodica Duellatorum, 2(1), 149-177. https://doi.org/10.36950/apd-2014-005

3. Gassmann, J. (2019). The Use of the Crossbow in Medieval Cavalry. In A. Ropa and T. Dawson (Eds.), The Horse in Premodern European Culture (pp. 87-104). Medieval Institute Publications. https://doi.org/10.1515/9781501513787-007

4. https://www.imdb.com/name/nm7801403/