Karel Vos (1874-1926) was a prominent figure in Anabaptist historiography, dedicating his life to studying and documenting the history of the Dutch Mennonite tradition. Despite limited access to archives, he conducted meticulous research and adopted a critical approach to historical analysis. His commitment to truthfulness in writing aligned with the principles of the Rankean Dutch Historical School. This also pointed to the presence of Anabaptist bishops from the Lower Rhine in the 1540s and 1550s. However, Vos’s views on Anabaptist history sparked controversy, as he believed revolutionary principles dominated the movement until 1540. Vos’s 1914 biography of Menno Simons remains an inexhaustible source, even if his work did not receive adequate recognition. Beyond his historical contributions, Vos actively engaged with the Anabaptist cause in his writings and demonstrated talent as a historical columnist. However, his exclusion from the academic circuit may have led to his undervaluation as a historian, both during his lifetime and in the years that followed.