Despite the particularities that can be presented in the different legal systems, there is no doubt that the institution of forced expropriation is a common heritage of western public law. For this reason, although it has had its own evolution, the disease due to the specific problems facing each legal system presents common features, responds to the problem and registers lines of development with parallel names. This is evident in the present book, which summarizes the work of fourteen researchers from seven countries in America and Europe, which offers a broad, rich and exhaustive view of this institution, a characteristic of classic administrative law and essential within contemporary administrative law.