Two layers of law
Roman civil law is the body of private law that governed Roman citizens: ownership, contracts, inheritance, family and wrongs done by one person to another. It grew from two main sources. One was the old civil law proper, the ius civile, rooted in custom, statutes and, above all, the Twelve Tables. The other was the work of magistrates called praetors, who adjusted and expanded legal remedies through their yearly edicts.
The two layers often worked together, but they were distinct. Roman writers contrasted the strict rules of the ius civile with the more flexible law created by the magistrates, sometimes called honorary law because it came from the holders of public office.
What a praetor did
The praetorship was an annual magistracy of the Republic. According to Roman tradition, the first praetor to administer justice in Rome was appointed in the later fourth century BCE, and a second, who dealt with disputes involving foreigners, was added around the middle of the third century BCE, in the era of the Punic Wars. More praetors were added over time as the state grew through Roman expansion. Praetors were elected, served for a year, and often held other duties, such as governing provinces.
A praetor did not generally decide the facts in a private case. Instead, he heard the parties, decided whether a legal remedy existed, and defined the issue to be tried. The case was then sent to a judge, usually a private citizen chosen by the parties, who heard evidence and gave a verdict. This division, between the magistrate who set the legal framework and the judge who decided the facts, was a defining feature of Roman procedure.
The edict
At the start of the year, a praetor published an edict, a public notice setting out how he would exercise his office. Sources describe it as being displayed on a white board in the Forum, where citizens could read it. It listed the situations in which he would grant a remedy, and often included standard wording for the formula, the short written instruction that framed the case for the judge.
The edict was not a statute passed by an assembly. Praetors had no formal power to make law, but because their decisions on when to grant a remedy had practical force, the edict in effect created new rights. A man who had no claim under the old civil law might receive protection if the praetor announced he would hear such a case. In some situations the praetor could also refuse a remedy that the strict law would have allowed, if enforcing it would be plainly unfair.
Most of a new praetor’s edict was carried over from his predecessor, with changes where needed. This is why the edict is often called a continuing or perpetual edict. Over generations, a stable body of procedures built up, even though each praetor was formally free to depart from it.
Formulary procedure
The early civil procedure relied on fixed spoken formulas and gestures, which were strict and unforgiving: a mistake in wording could lose the case. In the second century BCE, a new method became established, the formulary procedure, in which the parties agreed on a written formula. A Roman statute usually dated to this period, the Lex Aebutia, is traditionally linked with this shift, though scholars discuss its exact role.
The formula allowed greater flexibility. It could include defences, such as a plea that the claimant had acted fraudulently, which the old civil law did not recognise. This gave praetors a practical way to introduce ideas of good faith and fairness into private law.
The jurists and codification
Alongside the magistrates stood the jurists, educated men who gave opinions on legal questions. Their writings, on the edict and on the civil law, shaped how both were understood. Under the emperor Hadrian, in the early second century CE, the text of the edict was reportedly revised and fixed by the jurist Salvius Julianus, and after that it was no longer altered by praetors. This is the form of the edict that later writers commented on. The original text survives only in fragments quoted by later authors.
Roman law was eventually gathered into large compilations in the sixth century CE under the eastern emperor Justinian. His Digest collected excerpts from the jurists, and the Institutes provided a textbook. The collection, later known as the Corpus Iuris Civilis, was rediscovered in medieval Europe and studied in universities.
Why it matters
Roman civil law is often called the foundation of the civil-law tradition used in much of continental Europe, Latin America and elsewhere. Concepts such as ownership, obligation and contract, as well as the habit of organising law into categories, owe much to Roman sources, although they were reshaped many times. It is fair to say that these systems drew on Roman law rather than copying it.
The praetors’ contribution deserves attention for another reason. It shows how law can develop through administration and practice rather than through legislation alone. A magistrate who announced how he would act, year after year, helped to turn custom into predictable rule. The Roman Senate and assemblies passed statutes, but a good deal of the everyday law governing the daily lives of ordinary people was shaped by officials such as these. Historians still debate how much the praetors acted deliberately as reformers and how much they simply responded to the needs of a growing commercial city.