Objectives:
Study on the exercise of the right of pontifical legation during the time of the roman question, when the Holy See was deprived of territorial sovereignty after Italian unification.

Material and methods:
Papal documents and works of the doctrine on the foundation of the international subjectivity of the Holy See

Results:
During the time of the Roman question, between 1870 and 1919, the Holy See continued to exercise its international subjectivity by sending and receiving diplomatic representatives, despite being deprived of its territorial power. The States continued to recognize such international subjectivity and the right of pontifical legation based on the norms of international law and not on the basis of Italian domestic law, embodied in the Law of Pontifical Guarantees. The authors, on the other hand, was divided between those who defended the pontifical position and the Italian position.

Conclusions:
The recognition by the States of the capacity to exercise the right of pontifical legation by sending and receiving diplomatic representatives, without the existence of a territorial support, it could only be due to the spiritual power of the Holy See, which together with the temporal, that it was exercised since old times.