The work aims to show of Charles V, his conciliatory and the great efforts and concessions that had to be carried out according to the circumstances (despite of the enormous problems of state that faced, the strong pressures and the intrigues that he suffered), to try to achieve the peace for which he would struggle, and the permanent search for the unity of Christendom; emphasizing his patient mediation, his universalistic and ecumenical spirit, despite his great conviction of erasmian orientation, clearly Catholic without ambiguities, his conviction that the church needed to be reformed; His permanent request to hold a Unity Council; As well as its different performance before Protestantism in Germany (listening and mediating) through diets and in Spain demanding that the Inquisition Act.