Secondary teachers in the unified Italy: a group portrait with a zoom

After the unification of Italy in 1861 one of the main problems was the creation of a system of instruction to plan curricula and programs, teacher education, textbooks. Mathematicians were very active in this construction and some of them also had important official roles in the government. In this context important initiatives for the professional development of mathematics teachers were carried out: publication of good mathematics textbooks and books on mathematical culture for teaching, and the foundation of journals and associations. Mathematics teachers occupied a leading position in these actions. In this concern a question arises: “Who were the teachers animating these important initiatives?” In this paper I present some elements that help to answer this question by outlining some general characteristics of the mathematics teacher profession of those times and by illustrating the way the profession was lived by the founder of an important journal for mathematics teachers.