Over the last 40 years, exploring the possible interrelations between the history of mathematics and mathematics education has gradually emerged as an interdisciplinary domain of educational research and practice, and entered a maturity stage during the last two decades. This development calls for an account of the general issues concerning the rationale and main themes underlying research and applications in its context, and the foundational issues addressed as a result of its interdisciplinary character. Therefore, after explaining the perspective characterizing work in this domain (what has been called the HPM perspective), we present the main themes along which current research is conducted and we analyze the main issues and concerns raised by current research in this domain, with due reference to recent publications. Papers in this issue further develop the key research strands shaped by these main issues and concerns from a variety of perspectives; in particular, papers address the theoretical points related to the interdisciplinary character of this domain (e.g., the role of history in promoting and developing STEM education more profoundly), and the design of innovative teaching approaches based on original sources (e.g., how non-didacticized resource material can motivate mathematically rich tasks without requiring too specialized knowledge in the history of mathematics). These papers also suggest fresh avenues for research, some bearing on potential methodological connections between mathematics, education, and history (e.g., the possibility of different readings of original sources that reveal the complex interrelations among historical knowledge, teaching objectives, and pedagogical practices), and some bearing on the implementation, evaluation, and dissemination of designs connected to the history of mathematics, in teaching at all levels of education (e.g., development of curricular material based on original texts, offering new learning opportunities in relation to core topics in university mathematics). We conclude with a brief description of each contributed paper.