(i.) The control over priesthood and cultus belongs to the history of religion rather than to that of constitutional law, and it chiefly presents a legal aspect in connexion with the question of religious jurisdiction. The difficult questions that arose in Republican times from the clashing of the religious and the civil power could hardly have been heard of as yet, for the supreme control of both was vested in the same man. But the very nature of this disciplinary jurisdiction over priests has been a matter of some dispute. The favourite hypothesis of a family jurisdiction has been applied to the case, and the hypothesis may conceivably be correct so far as the Flamens and the Vestals are concerned, although even in this sphere it is doubtful by what paternal right the head of religion could do the Vestal’s paramour to death. Other phases of the power are still more inexplicable on this ground. A right of punishing augurs for a breach of ritualistic rules survived into the Republic, and seems to be a jurisdiction exercised over them as members of a religious body. There is, however, no trace of the priesthood holding a privileged position, and in all secular matters its members are subject to the ordinary law. Such privileges as they possess rest on religious scruples. When the Flamen was caught (captus) for the god, he became free from the paternal power,[207] and the civil authority could not compel him to take an oath.[208] The persons of the Vestals were inviolable;[209] the sanctity of both Flamens and Vestals also invested them with the right of asylum. The bonds were struck off the prisoner who took refuge in the Flamen’s house; and, if the criminal on the way to punishment met him or the Vestal, he could not be scourged or executed on that day. But it is only in these two cases that the severance from the world is strongly marked; we have no reason for believing that, in the earliest period of Rome’s history, the members of the religious orders were isolated from the mass of the people with privileges and a jurisdiction all their own.

The control of the cultus, and the maintenance of its purity, are marked as one of the earliest duties of the pontifex maximus, and must have belonged to the king. It is he that sees that no ancestral right is neglected, no foreign one acquired.[210] Here we have a religious power that governs more than the priesthood; the maintenance of the sacra privata are as important in its eyes as that of the sacra publica, and its supervision must have extended beyond the limits of the Patriciate; for it is impossible to believe that religion cared only for the sacra of the patrician clans, and aimed only at preventing them from corrupting their ancestral worship. The Plebeian and the client were under the protection of the gods, and might bring down a curse on the community by reckless innovation or neglect.

(ii.) The control exercised by fas over the citizens’ life in matters not immediately connected with ritual and worship may be first illustrated by its penal sanctions. We cannot, indeed, say that there was a time when the Roman law regarded every crime as a sin, for from the very first we are confronted with a dualism, and religious and secular sanctions exist side by side. But religion has left a deeper impress here than elsewhere—in the name given to punishment,[211] in the form of its infliction, in the still stranger fact that, by the disappearance of religious sanctions, breaches of obligation that the modern world regards as crimes remained unpunished by the secular arm.

The punishment for sin must be some form of expiation. This is the piaculum adjudged in the monarchy as in Republican times by the head of religion; and not adjudged arbitrarily, for even by the close of the monarchical period classes of offences had doubtless been drawn up by the pontiffs with the equivalent expiation, which was directed to avert the anger of the gods from the whole community. Apart from the regularly recurring lustrations at the census—the consequence of the sense of universal sinfulness in the community—individual misdeeds could be expiated in this way. Such was a murder that was unintentional or in which mitigating circumstances were present,[212] and such was the violation of the chastity of Juno’s person through the touching of her altar by a paelex.[213] In graver cases expiation could only be accepted where there was no intent,[214] as in the wrong done to a god by swearing falsely in his name.[215] There was also a class of deadly sins for which the gods would accept no atonement but the life and the goods of the sinner himself. Amongst the acts which called forth this consecratio capitis were the violation of the relations of client and patron,[216] the ill-treatment of elders by their children,[217] the pulling up or alteration of boundary stones,[218] the destruction of a neighbour’s corn by night.[219] The god thus appeased was often the deity who was held to be specially offended by the act; but sometimes the head and the goods were not dedicated to the same divinities. The person was adjudged to Jupiter, the dispenser of life; the landed property to the gods who nourish the human race, Ceres and Liber.[220] This custom of consecration gradually ceased to have its literal fulfilment. A man might still be declared sacer, but excommunication had taken the place of immolation. Such a man was cut off from all divine and, therefore, from all human help, and his slayer was blood-guiltless.[221] This theory, of a man being cut off from the community while his life was spared, became of great importance in the history of Roman criminal law. It survived in the “interdiction of fire and water” (aquae et ignis interdictio), and familiarised the Romans with the idea that the severest penalty did not require the sacrifice of life.

In matters of private law we have already witnessed the presence of religion in marriage, adoption, testament, and the transmission of the sacra. Its authority may be further illustrated by the formularies of civil procedure. Here the form of words was all-important, and in the early Republic all binding formulae, whether for oaths that were to be effectual, for vows or for consecration, were known only to the pontiffs. The solemn forms of law (legis actiones) issued from the same authority, and in one of their most frequent manifestations, the sacramentum, the procedure was distinctly religious.[222] But who could say whether the king, when he gave the prescribed form of words for an action, acted as a religious or a civil head, as the representative of fas or jus? Here we are on the borderland between the two.

(iii.) Nations know no common jus, and fas is the sole support of international law. Each people is protected by its own divine guardians; hence a war of two nations is a contest between their gods, and a treaty between two peoples a compact between their respective divinities. But each nation is to some extent under the protection of the other’s gods. Jupiter of Rome is powerless if the war commenced by Rome is unjust, and will punish his own people if they have stained his honour by violating a treaty. Even though there is no belief in community of guardianship, the rights of other peoples are still conceived to be under the protection of the Roman gods.

These beliefs necessitated elaborate religious preliminaries to the declaration of a war in order that it might be just and holy (justum piumque),[223] as well as ceremonies for the conclusion of a peace that was to bind the public conscience (fides publica).[224] Such a ritual may have been performed, originally, by the king himself; but tradition states that, at a very early period, a special guild of priests, the Fetiales or public orators, were appointed for this purpose.[225] Their chief functions were the declaration of war and the conclusion of peace, but the ritual observed in both of these acts may be more appropriately described when we are dealing with the international relations of Rome. There were other religious preliminaries to a war which, though not necessitated by divine law, it was highly expedient to observe, in order to increase the chances of victory. Vows (vota) were offered to the native gods, and for these to be valid they must be couched in a form prescribed by the pontifical college.[226] And sometimes the king, before a battle or a siege, chants an incantation (carmen), the purport of which is to weaken the loyalty of the enemies’ gods to their worshippers, and to bring them over to the side of Rome. He bribes them with temples, offerings, and the honours of a special cult.[227] If the bribery is effective and the city falls, he must carry out his pledge. The conquered gods are received at Rome; and their worship is guaranteed by the distribution of their cults over the patrician clans.[228] The instances preserved of this devotio and evocatio naturally date from the time of the Republic.[229] During this period the forms are prescribed by the pontiffs. But the antiquity of the procedure is beyond question. The results of evocation on the part of the king, who was his own pontiff, are manifested in the local worships of the conquered towns of Latium, which found an early home at Rome.

If we turn from the religious to the civil powers of the king, it is easier to estimate their extent than to determine the precise modes of their exercise. Later belief credited him with the sole executive power of the state. The Roman kings possessed πᾶσα ἀρχή, and exercised the imperium at their own discretion.[230] Such statements are not surprising if we remember what is implied in the imperium, and that there appear to have been no legal limitations to its exercise during the monarchy. Imperium implied the combination of the highest military and civil authority; it united jurisdiction with command in war, and it included the further right of intercourse with the people (jus rogandi); while the later restrictions on this power, the limitation of office by time or by colleagueship, had not yet been created. The king held office for life, and he had no colleague; for the other officials in the state must have been mere delegates whom, in the strict theory of the constitution, he permitted to exist.

But if the king’s power was legally free from restraint, and we do not believe that there was any large body of leges binding his authority, it could not have been free from the limitations imposed by custom and constitutional usage. Customary law securing rights for the people is said to have been raised to the level of positive law by Servius Tullius.[231] But even the earlier usages must have formed a kind of code—such a code as that which contained the pontifical ordinances known as the leges regiae.[232] It was the belief in the existence of this early customary law which led to the later description of the king’s power as an imperium legitimum.[233] Amongst his constitutional obligations was that of consulting the Senate in any important matter.

There can be little doubt that the original council of elders (senatus) was a body of nominees selected by the king as his permanent advising body (consilium publicum).[234] In consequence the position of senator could not have been a life-office; there could neither have been any definite mode of attaining the dignity, nor any claim on the part of an individual to retain it. A new king might decline to summon some of his predecessor’s councillors; he might even, perhaps, change the personnel of his advisers during the course of his reign. It was in later times believed that the freedom of selection was so great that no stigma attached to members who were “passed over” (praeteriti) by the king.[235]