Bartłomiej Walczak, born 1978, is a nuclear physicist, who works as a film editor and desktop publisher. Renaissance martial arts have been his passion since 1999, and his work with the technical sources began in 2000. In 2002 with Grzegorz Żabiński he published a book Codex Wallerstein: A Medieval Fighting Book from the Fifteenth Century on the Longsword, Falchion, Dagger, and Wrestling. He is a director of the Polish branch of ARMA, the Association for Renaissance Martial Arts, and one of the founding members of HEMAC, the Historical European Martial Arts Coalition. His areas of expertise are longsword and dagger, unarmored and armored combat. Currently he is working with Żabiński on a book containing transcription and translation plus full comparison and interpretation of the Kraków and Vienna Gladiatoria manuals.
- Walczak, Bartłomiej. "Judicial Armoured Dagger Combat of Gladiatoria and KK 5013". Masters of Medieval and Renaissance Martial Arts. Ed. Jeffrey Hull. Boulder, CO: Paladin Press, 2008. ISBN 978-1-58160-668-3
- Żabiński, Grzegorz and Walczak, Bartłomiej. Codex Wallerstein: A Medieval Fighting Book from the Fifteenth Century on the Longsword, Falchion, Dagger, and Wrestling. Boulder, CO: Paladin Press, 2002. ISBN 978-1-58160-585-3