Parties in civil trials

In Roman law the term actio signified a person's right to institute proceedings in a court of law.^[417] The same word was also used to denote a lawsuit.

The term iudicia legitima was used to denote trials in which both litigants were Roman citizens and which took place in the area of Rome before one judge only.^[421] By contrast, the term iudicia imperio continentia referred to trials in which any one of these requirements was absent (e.g. trials in which one or both parties were foreigners). The former were regulated by statutory law {lex), whereas the latter were based upon the imperium of a jurisdictional magistrate. Slaves were not allowed to be involved as parties in any trial.^[422] In trials concerning a slave's freedom {causae liberales) the slave was represented by another person {adsertor libertatis) who argued for or defended the right to freedom of the slave concerned. Women, children and persons suffering from some form of mental disorder were unable to appear in court alone. Thus, with respect to the iudicia legitima, women sui iuris (i.e. women who were neither under their father's patria potestas nor under the control of a husband) could not take part in any court proceedings without the supervision of their guardians {auctoritas tutoris'). Children and insane persons were usually represented in court by their tutors or guardians {tutor es, curatores).

It was not required that the parties to a dispute should attend the court proceedings in person. A party was allowed to conduct his case through a representative who, depending on the way in which he was appointed, was referred to as cognitor or procurator. The cognitor was nominated by the party he was to represent in the in iure (before the magistrate) phase of the proceedings in a formal way and in the presence of the other party.^[423] If the party represented by the cognitor was the defendant, the latter had to provide security that he was going to abide by the decision of the court.^{face="Times New Roman">[424]} A procurator could be appointed at any time (it was not required that he be nominated before the magistrate), with or without the knowledge of the other party.^[425] However, a procurator appointed by the defendant was under an obligation to give guarantees that the party he represented would carry out the court's decision.^[426] Similarly, a procurator representing the plaintiff had to provide security that his acts would be adopted by the party who appointed him {dominus negotii) so that the defendant could be sure that the plaintiff would not bring against him a new action for the same object.^[427] The representative conducted the case in his own name, not in the name of the person whom he represented.