The reports of the vacancy of centres historic cities and the development of peripheries(outskirts) raise a question as for the place(square) of the genealogical knowledge of evolutions of the historic city. How to wonder to reconquer social link in the historic cities and to register them in long-lasting(sustainable) circular savings(economies)? Do their architectures, and their knowledge, allow to mobilise actors' new games(sets) in cultural, economic, ecological, social systematic services(departments)?