Published in 1969, Istituzione del Principe Cristiano by Gaspare De Caro is a historical and political study examining early modern treatises on ideal Christian rulership. The book analyzes texts from the 16th and 17th centuries that define the moral, religious, and political foundations of princely authority within a Christian framework. Structured thematically, it discusses figures such as Erasmus and other political thinkers, tracing the evolution of Christian political theory. Addressed to scholars of political philosophy, early modern history, and religious thought, it contributes to understanding the intersection of ethics and power.