French nineteenth century secondary education may only be frequented by a small fraction of young boys, it is nonetheless the focal point of the public education in construction, which allows to consider public secondary schools as a privileged observatory of schooling and public policy before the IIIrd Republic. In this regard, this dissertation studies the transformation, between 1830 and 1880, of 45 collèges managed by town councils into lycées administrated by the state. These conversions are studied through three lines of research. First of all, the analysis of the roles and obligations of each of the actors involved in the process brings to light the educational motivations of the transformations, as well as their financial and urban ...