Birth determines the existence of man and with it his legal projection until the end of his existence occurs. On this natural dimension of the human being, life and death are projected in the world of Law as events that generate effects that affect the individual member of a social community. The processes of birth and death have been identified throughout the legal tradition as a conditio iuris to determine the existence of man, understood as this, either as a subject of law or as a natural person. In the words of DOMINGUEZ MILLAN "man has never been considered with his own legal value inherent to the fact of being a man; his condition depended on the circumstances in which he found himself with respect to the groups that constituted the Country and specifically in Rome, it was necessary that he be part of a family". Although in current Law it is enough to be a man to be a person in the sense of a subject of Law, the same did not happen in the Roman world where the biological conditions that are required in our time to verify human existence and therefore to be a person- subject of law, they only determined the existence of man as a natural person, his civil personality being conditioned to the position that the born child would occupy within the domestic community. Thus, the legal position of the cives, at least in the most archaic times of the ius civile, will depend on its legal submission to the power of another cives, male, free and independent, the paterfamilias. On this basis we will analyze the legal dimension involved in the process of life and death of the person-subject of law, in order to identify the assistance measures that the Law regulates in each of its periods, with a view to complementing the capacity of those who, due to age, have ceased to be subject to parental authority and cannot govern themselves independently in aspects of public life.
