In the first few centuries of the Principate, the practice of distributing functions among different sets of authorities also prevailed in the administration of justice. Certain areas of civil and criminal jurisdiction remained with the traditional republican magistrates, while others were transferred to imperial authorities. As the republican element of the constitution withered over time, the latter surpassed and finally replaced the former. In the same period, the senate assumed an original jurisdiction of its own in cases involving certain crimes of a political nature. Whenever the imperial branch took over judicial functions the procedure adopted differed considerably from the traditional formulary procedure. The trial consisted of only one stage and judgment was delivered by a state official with an extensive discretion in applying both the procedural and substantive norms. As a result, litigation could proceed in a simpler and more convenient fashion while the juridical and administrative activities of the state were mainly captured by a central authority. In addition, a hierarchy of courts emerged and a relatively elaborate system of appeals developed from the lower to higher tribunals. The new form of procedure, known as cognitio extraordinaria or cognitio extra ordinem, did not play such an important a role in the development of Roman private law as the formulary procedure. Nevertheless, it engendered several notable principles that coincide in several respects with modern principles of civil procedure (especially in civil law jurisdictions).

Civil procedure

The formulary procedure

As we have observed, during the late Republic the formulary procedure gradually replaced the earlier legis actio procedure. By the end of this era, the formulary procedure had evolved as the main form of civil procedure in Rome – a development that acquired statutory sanction by Augustus’ judicial reform legislation of 17–16 BC (leges Iuliae iudiciorum publicorum et privatorum).1 In the altered conditions of the late Republic, the formulary procedure permitted the jurisdictional magistrates to introduce novel rights and remedies to accommodate the new socio-economic relations of an increasingly sophisticated society. For a great span of time after the establishment of the Principate the normal jurisdiction of the republican magistrates was fully maintained and the per formulam procedure remained the customary method for initiating legal action in disputes relating to private law. As explicated previously, the relevant procedure was divided into two phases. In the first place (in iure), the praetor determined the admissibility of the plaintiff’s claim, i.e. whether the plaintiff should be granted an action at law. If the praetor was satisfied that the plaintiff had an arguable case, the appropriate formula was composed that nominated the judge (iudex) to try the case, stated the matter in dispute and prescribed the consequences of the judge’s decision. The trial occurred in the second phase (apud iudicem) where the judge listened to the parties’ pleadings, assessed the evidence and rendered a verdict in accordance with the formula agreed in the in iure phase.

The only element that changed in the formulary system during the Principate period was the function of the praetorian edict. As noted, in the closing years of the Republic the productive strength of the praetorian edict as a source of law faded and praetorian initiatives became increasingly rare. This trend prevailed during the Principate age and as the praetor’s ability to develop new legal remedies diminished, the changes to the edict were based on measures introduced by other law-making agencies, such as statutes and senatorial resolutions. The creation of law administratively by the praetor finally ended during the reign of Emperor Hadrian when the content of the edict was permanently fixed following its codification by the jurist Julian. Thereafter, any requisite changes to the edict could only be introduced by imperial enactment. Although no longer an independent source of law, the praetorian edict perpetuated its contribution to the administration of private law well after the formulary system had fallen into abeyance in the third century AD.2

The cognitio extraordinaria

Since the early Principate age, the emperor or a state official acting on his behalf assumed, or was accorded, the right to decide certain cases when the positive law did not provide remedies. This right was effectuated by a procedure called cognitio extraordinaria or cognitio extra ordinem. The cognitio procedure could be employed not only in cases involving private disputes, but also in criminal cases and disputes between private citizens and state organs. The new procedure probably originated from the early practice that allowed jurisdictional magistrates to directly deal with certain cases either on the application of a party or on their own initiative. The magistrates tackled these cases by using their administrative authority to cut through the formalities observed in regular court proceedings. The procedure was widely adopted in the provinces during the later republican period, especially in criminal cases. It was also engaged in cases involving private disputes between foreigners and cases relating to disputes between Romans when not enough Roman citizens were available to serve as judges. Such cases were addressed by the provincial governor either directly or through a delegate (iudex pedaneus), without observing the rules governing the ordinary procedure. From the time of Augustus, the cognitio extraordinaria was the only form of procedure used in the imperial provinces where the administration of justice was directed by imperial officials who acted as representatives of the emperor (legati Augusti pro praetore). By the early second century AD, it had become the regular form of procedure in the senatorial provinces. In Rome and Italy the cognitio extraordinaria was employed from the beginning of the Principate, although not on a regular basis. In the course of time, the new procedure gradually superseded the formulary procedure. By the end of the third century AD, it was the ordinary form of procedure throughout the whole empire.3

The establishment of the cognitio procedure as the main form of legal procedure was partly due to its great simplicity and flexibility. It also partly derived from the fact that, in accordance with imperial ideas, it facilitated the centralization of state authority. The cognitio extraordinaria was a device – as had been the formulary technique in the past – facilitating the judicial care of legal situations when the existing positive law did not offer appropriate solutions. At the same time, it became the vehicle for the subsequent evolution of the imperial jurisdiction that competed with and, if necessary, replaced the jurisdiction of the ordinary (republican) jurisdictional magistrates. As the imperial system developed, the state increasingly intervened in the sphere of law. This entailed the situation where legal disputes were no longer based on an agreement between the parties to present such a dispute before a judge, but on the power of the authorities to place a dispute before its officials, attain a resolution and execute the decision. A petition by one of the parties usually initiated the state intervention, but the emperor could also set it in motion by a procedure called evocatio that transferred the case to his extraordinary jurisdiction. Thus, cases of special importance could be withdrawn from their regular forum for determination by the princeps-emperor sitting, as a rule, in consultation with his legal experts. The emperor could also delegate his jurisdiction to subordinates designated in accordance with the subject matter of the particular case. In Rome and Italy the magistrates concerned were the special praetors, such as the praetor de liberalibus causis,4 the praetor tutelarius5 and the praetor fideicommissarius6 and various imperial officials, such as the praefectus praetorio, the praefectus urbi, the praefectus annonae, the praefectus vigilum and the procuratores fisci.7 As noted, in the provinces the administration of justice was in the hands of the governors (praesides). Often these officials exercised their judicial functions through delegates (iudices dati or pedanei). These delegates were usually lower state officials appointed by their superiors. This contrasts with the iudices appointed by the praetor under the formulary system, who were private citizens chosen by the parties.8 The practice of appeal from the lower to the higher instance and finally to the emperor ultimately emanated from this technique of delegating judicial functions from the princeps-emperor to his high-ranking officials and the latter’s authority to sub-delegate the case to their subordinates. The rulings of the emperor as judge in the first instance or in the case of an appeal (decreta) were theoretically only binding in the particular case. In the course of time, they came to be regarded as authentic statements of law and binding in subsequent similar cases. Thus, a new body of substantive legal rules evolved from the operation of the new imperial branch of the administration of justice. This new body acquired equal rank with the two traditional legal systems: the ius civile based on the Law of the Twelve Tables and the subsequent comitial legislation; and the ius honorarium derived from the edicts of the republican magistrates.

The most significant feature of the cognitio procedure was the abolishment of the two phases in iure and apud iudicem