Saavedra's main work is the Idea de un Príncipe político cristiano representada en cien empresas, written in Germany, published in Münster in 1640, which, as a whole, is the best Spanish political treatise of the century . XVII, one of the many that were written, it would seem, to prop up the decadent and shaky monarchy. The work had translations into many European languages and into Latin, and multiple editions until the last one by Vicente García de Diego in 1927. There are 101 chapters called empresas (name that in the sixteenth and seventeenth centuries designated an art and an artificial, widespread literary genre). The dissertation of each chapter is premised on an "enterprise", i.e. a symbolic, allegorical design, accompanied by a Latin motto, both forced to have an ethical and political meaning, which each give matter and argument to an intended comment to trace the ethical and political qualities that must adorn an imaginary perfect prince, the prototype of the Christian prince.