The specialization that mathematics education research has undergone in the past decades has led to a sense of division and disconnection between mathematicians and mathematics education researchers. This chapter deals with the possibilities that the history of mathematics may afford to reduce the divide. Although the recourse to the history of mathematics is an interesting prospect, it unavoidably induces new problems. A range of tensions becomes visible among the involved communities of teachers, historians of mathematics, mathematics education researchers, and mathematicians. Some of these tensions are investigated in this chapter, in particular in the case of a hermeneutic reading of original sources. The tensions that the history of mathematics induces, it is argued, may function as a way to foster a critical reflection and dialogue to contribute to a rich multi-layered understanding of mathematics, its history, and its teaching and learning.