4This volume contains the contributions presented at the Xth Early Career Researchers' Conference on History Didactics 2020, Johannes Gutenberg-University Mainz. The biennial conference is part of the program the German Society of History Didactics offers to increase discussions and transparency in research within the academic discipline and beyond. The articles in this volume represent the wide range of current topics and methodological approaches in the discipline including theoretical discussions as well as empirical research.