 All of them were "Ghibellines" (supported the idea of the Empire being over the pontificate) and in favor of Frederick I, of whom they were contemporary.Around the same time, with some decades of difference, a systematization of the ecclesiastical law took place, which was going to give birth to the canon law in all its fullness.Romanists and canon lawyers were brothers of mentality and duties, although the later defended the pontifical rights.