During the second half of the nineteenth century and early twentieth century the discipline of secondary mathematics was gradually built in Portugal and certified teachers, textbooks, programs, special teaching techniques emerge. This consolidation process ends with the emergency of school subjects that develop some kind of autonomy as Chervel puts it. This article discusses how the school discipline of mathematics in secondary education in Portugal was set. This process is inseparable from teacher training and so we will observe professional legitimation processes paying special attention to ways in which autonomy has been building and modifying over time.