The research was carried out with a teacher educator employed in a Bachelor’s Degree Program of a Brazilian institution. The aim was to assess the processes concerning the development of teachers throughout teachers’ education, following the principles of Cultural-historical theory. The theoretical-methodological procedure applied was the didactic-formative intervention, understood as a collective investigation-education process that intervenes with teaching. Such intervention happens with the development of interdependent and simultaneous actions of training, planning and implementation of teaching and studying activities. The intervention comprised questionnaires, interviews, classroom observation, document analyses and training meetings. The analyses demonstrated that the imitation-creation process is essential to teachers’ development. Theoretical principles are only accomplished with creations that help to materialize the teaching practice. Therefore, the training must allow the construction of theoretical concepts that are experienced in the teaching practice through imitation-creation. This process is understood as a movement that constitutes teachers’ education, being established in the relationship between principles and theory’s creative experience, i.e. the creation of teaching possibilities that are developed in the theory-practice unit.