In this study we examined the impact of four teaching sessions on the history of ancient Mesopotamian mathematics, in a 10th -grade classroom. The sessions were taught primarily with historical objectives by researchers in the history of ancient mathematics. We reconstructed historians' practices and ethos. The presence of the researchers provided the opportunity to study a sequence in which history was taught 'as a goal'. Moreover, there was no intermediary between the historians and the teaching given to the students, which allowed us to study directly the transposition choices that interested the researchers. We cross-referenced the qualitative and quantitative results of some of the previous findings with the researchers' task design and discourse. We focused on two aspects, namely, students' relationship to mathematics as a scientific activity, and the effects of the students' encounters with the tools and ethics of the history researcher. We found evidence suggesting that students may have made progress in their perception of mathematics 'as an activity' and that a certain 'dépaysement' emerged. Further, the emergence of debates on the nature of historical sources suggests that the teaching of history 'as an endeavor' also seemed to have affected the students. We conclude by proposing some methodological guidelines for future studies.