Something must be said of the formal instrumentality by whichthe principles and distinctions associated, first with the Lawcommon to all Nations, and afterwards with the Law of Nature,were gradually incorporated with the Roman law. At the crisis ofprimitive Roman history which is marked by the expulsion of theTarquins, a change occurred which has its parallel in the earlyannals of many ancient states, but which had little in commonwith those passages of political affairs which we now termrevolutions. It may best be described by saying that the monarchywas put into commission. The powers heretofore accumulated in thehands of a single person were parcelled out among a number ofelective functionaries, the very name of the kingly office beingretained and imposed on a personage known subsequently as the RexSacrorum or Rex Sacrificulus. As part of the change, the settledduties of the Supreme judicial office devolved on the Praetor, atthe time the first functionary in the commonwealth, and togetherwith these duties was transferred the undefined supremacy overlaw and legislation which always attached to ancient sovereignsand which is not obscurely related to the patriarchal and heroicauthority they had once enjoyed. The circumstances of Rome gavegreat importance to the more indefinite portion of the functionsthus transferred, as with the establishment of the republic beganthat series of recurrent trials which overtook the state, in thedifficulty of dealing with a multitude of persons who, not comingwithin the technical description of indigenous Romans, werenevertheless permanently located within Roman jurisdiction.
Controversies between such persons, or between such persons andnative-born citizens, would have remained without the pale of theremedies provided by Roman law, if the Praetor had not undertakento decide them, and he must soon have addressed himself to themore critical disputes which in the extension of commerce arosebetween Roman subjects and avowed foreigners. The great increaseof such cases in the Roman Courts about the period of the firstPunic War is marked by the appointment of a special Praetor,known subsequently as the Praetor Peregrinus, who gave them hisundivided attention. Meantime, one precaution of the Roman peopleagainst the revival of oppression, had consisted in obligingevery magistrate whose duties had any tendency to expand theirsphere, to publish, on commencing his year of office, an Edict orproclamation, in which he declared the manner in which heintended to administer his department. The Praetor fell under therule with other magistrates; but as it was necessarily impossibleto construct each year a separate system of principles, he seemsto have regularly republished his predecessor's Edict with suchadditions and changes as the exigency of the moment or his ownviews of the law compelled him to introduce. The Praetor'sproclamation, thus lengthened by a new portion every year,obtained the name of the Edictum Perpetuum, that is, thecontinuous or unbroken edict. The immense length to which itextended, together perhaps with some distaste for its necessarilydisorderly texture, caused the practice of increasing it to bestopped in the year of Salvius Julianus, who occupied themagistracy in the reign of the Emperor Hadrian. The edict of thatPraetor embraced therefore the whole body of equityjurisprudence, which it probably disposed in new and symmetricalorder, and the perpetual edict is therefore often cited in Romanlaw merely as the Edict of Julianus.
