The Epistemic Beliefs of History Teachers dataset is one of the outputs of the History+ project. The History+ project aimed to examine the potential for transforming the methods of teaching history at middle schools. The project was announced by the Ministry of Education, Youth and Sports of the Czech Republic in the form of a so-called experimental intervention. It focused on the development of students' key competencies, including thinking on history and inquiry skills with historical sources. At the same time, in connection with the 2030+ Strategy, the project verified a way of supporting schools in actually transforming their teaching methods and creating a model for working with teachers. The History+ project was launched on 1 February 2021 in cooperation between the National Pedagogical Institute of the Czech Republic and the Institute for the Study of Totalitarian Regimes. The Epistemic Beliefs of History Teachers dataset is a part of the whole Teacher questionnaire dataset, which is available in its entirety as the "Teachers-entire dataset". Teachers' epistemic beliefs result from pre-test and post-test measures, first in the 2021/2022 and second in the 2022/2023 academic years. Participating teachers and their coordinators, also active teachers, responded. The intervention was primarily concerned with contemporary history taught in middle schools, so history teachers in the 9th grade of primary schools and in corresponding grades of multi-year Gymnasiums were primarily recruited. However, the project also involved teachers of Gymnasiums and secondary vocational schools where modern history is also taught. The collection was carried out using the internationally recognised and validated Beliefs in History Questionnaire translated and tested in the Czech environment by Říčan et al.