Authors copyright Murray J Leaf 2003

 Roman law defined itself as a systematic body of ideas and practices, and here too the definition served as a tool for making itself true. However, in this case the main vehicle for legal exegesis was not philosophy but history.  Roman history incorporates both the substance of the political and legal system  and an extraordinarily many-sided analysis of what did and did not work.

What follows is a much compressed paraphrase of what most educated people would have understood in the latter half of the nineteenth century as the development of  Roman law. It mainly follows Thomas Collet Sanders’ 1903 introduction to his translation of  The Institutes of Justinian supplemented, H. L. Havell’s 1914 Republican Rome and Livy.

There were three main constitutional epochs: the monarchy, the republic and the empire.  In all three periods the accounts analyze the constitution in terms of four main elements: the system of social classes, the public assemblies, the elected officials, and the substantive laws. The monarchy was a kin-based society with an elected king held in check by kin-group leaders.  In the republican period, government was based on elected officers and popular assemblies arranged in a complex system of checks and balances. The empire was centralized and totalitarian. As the systems differed, so did their basic view of the source of law and of the legitimacy of legal institutions. In general law was held to be the will of the Gods, but exactly how that will was to be known and expressed varied radically. For the monarchy, the king was the chief authority on the law. For the republic, the doctrine was vox populi, vox dei – the voice of the people is the voice of the Gods, on the understanding that “the people” in this sense was the people in formal assembly.  The Empire returned to the monarchial idea: “The emperor is the voice of the law.”.

In all periods, the social classes were clearly marked and a matter of public record.  At about the time of the end of monarchy, when myth begins to give way to history, there are two classes or orders and each is organized differently.  The dominant class are the patricians, also in different aspects called the patres and the cives. They were taken as the descendants of the true and original Romans and made up the political body, the  populus Romanum, whose organization and laws were fundamentally those of a largely agrarian tribal society with social position and power strongly based on family and gens (clan).  The patres alone had legal rights, including the rights to vote and hold office.  They alone made up the army and paid the taxes, and they alone were entitled to legal protection in their relationships with one another, the protection of the commercium and connubium. Commercium was Roman contract law. It provided forms to enter agreements, buy, sell, borrow, rent or pledge goods, adopt a person, or free a slave or a member of one's household.  Connubium was Roman family law, and conveyed the right to legally marry other citizens. It also allowed one to enter the Roman religious community – a prerequisite for voting and holding office (Sandars 1903:xviii).
The second order, the plebs, originally had none of these rights or duties. They neither served in the military nor paid taxes. They were forbidden marriage with the patricians and denied the commercium and connubium, although in principle the body of civil and criminal law applied to them as well as to the  citizens.

Although there was occupational diversity in both classes, the policy interests of the patres were those of large, well-capitalized, commercial farmers who produced crops like wine and oil and among other things could treat large areas of public land as their own for farming and grazing. The policy interests of the plebs were those of artisans and  small-scale peasant farmers growing a mixture of foodgrains, short of land and credit and with no access to state lands. One of the main themes in the histories written in the later republic was the struggle of the plebs for legal and political equality, the “struggle of the orders.”  But while the orders eventually merged, these opposed agrarian interests remained.

The relationship between the two classes was clientship.  Patrician families had plebian clients who worked for them and provided political support. The term client comes from the word meaning "listener."

In the monarchial system, the patricians were divided into three tribes (tribus), each tribe into ten curiae, and each of these in turn into ten decuriae, the gens (clans). The symmetry suggests the use of  a system for periodically regrouping families into the larger units.  The comitia curiata was a great council consisting of the heads of all the families.  The senate (from senex, old man), was a smaller body consisting of the 300 heads of each of  the gens. When legislation was required, it was formulated by the Senate and submitted for approval to the comitia curiata. If approved it was enforced by the king.  Kingship was not hereditary. The king was nominated by the Senate but elected by the curies (Sandars 1903:x). The term of office was not fixed. The king was the commander in chief, the chief priest (and in this capacity the principle authority on the law), and the supreme magistrate.

The sixth and penultimate king was Servius Tullius,  who reigned for forty-four years (578-534) until he was assassinated by his daughter and her husband, Lucius Tarquinius Superbus. Having seized the office by force Tarquin ruled by force, according to Livy (1.35) , murdering potential opponents, depopulating the Senate, forming foreign alliances to support his rule, not consulting as required in decisions, and, thereby, finally provoking the rebellion that initiated the republic in 509 BC.

Servius is credited with a series of constitutional reforms that set the stage for the republic, and Livy remarks that according to some writers he had wanted to abdicate in favor of a republican government.  Among other things, he undertook a census of the entire population and on this basis grouped every adult man into a system of military classes according to their wealth. In the republic, these classes became the basis of the system of election and the foundation of the plebs’ struggle for enfranchisement.

 There were five classes of infantry and two classes more at either extreme. The latter two were the equites and the proletariat. The equites (knights) were charged with maintaining horses and making up the cavalry, receiving an allowance from the state for the purpose.  The proletariat were those who had little or nothing and whose only obligation was to provide sons. Each class was divided into a number of “centuries” that were also voting bodies when assembled on the Field of Mars, outside the sacred boundary of the city as the comitia centuriata. Voting was by class. The majority in each century determined who got its vote.  There were initially 193 centuries in all. The equestrians and first class of infantry were divided into 18 and 80. Thus they alone held a majority. According to Livy, classes after the first two were called upon to vote only until a majority was obtained. The last classes were seldom called (1.43). Voting was by voice until 139 BC, when ballots were introduced.

Republican magistrates were divided into those who exercised imperium – the power to command – and those who did not.  Those who exercised imperium were elected by the assembly of centuries.  These were the highest ranking magistrates, consul and praetor and, later, censor, and curile aedile.  Election did not confer the imperium, however. That was done separately by the comitia curiata, which continued to exist and which voted separately to ratify the election.

Magistrates served for fixed terms of one year. While in office they were sacrosanct, inviolable in their person.  Initially, the chief magistrates elected by the assembly of centuries were praetors, "generals" with the closest counterpart of the king being the Praetor Maximus. The office had also existed under the kings. Soon, however, this was replaced by the office of consul. The consul was a divided office, one office held by two people.  Both had to act together, and either could annul the action of the other. It may have been intended that one of the consuls would be from the plebes, although this was not always done. In the event of a national emergency, the senate could direct one of the consuls to appoint a dictator. The dictator acted with the full authority of both consuls, but only for a term of six months. No one could be consul who had not previously served as praetor (Petit 1974:1096).

In theory, what a consul or praetor could do was limited only by the rank of his imperium, except that any magistrate could reverse the action of another whose imperium was equal or lesser and in capital offences the defendant had the right of appeal to the populace, represented by the comitia centuriata. The magistrate’s imperium was represented by the number of lictors that could accompany him.  A lictor was a person who bore the symbol of official power — the fasces, an arrangement of  sticks and an axe.  Within the city, the sticks were tied with thongs into a bundle around the axe.  Outside the city  the axe was exposed.   The symbolism reflected the derivation of the term lex, law,  from ligare, to bind.  The stated meaning was that within the city the magistrates were under the higher authority of the Roman populace; outside, they were not.

Writers disagree over whether praetors ceased to be elected for a time after the consuls were created and were later restored or whether they existed continuously (cf. Thomas 1976:15).  In any case, in 242 BC an historically important distinction was made between the praetor urbanus and the praetor perigrinus.  The first was to oversee law and legal disputes between Roman citizens. The latter was concerned with law in the provinces and disputes involving foreigners. The number increased to four after 227, six after 197, and 8 under the dictatorship of Sulla (82-79 BC).  Some of these were specifically to serve as provincial governors.

The Servian reforms are also traditionally credited with creating the comitia tributa, in which the old ethnically defined patrician tribes were replaced by tribes combining both orders and  defined by place of residence.  There were originally four in the city itself and sixteen in the outlying areas.  By 241 BC, the total had increased to 35. The comitia tributa could be convened by either a consul or a praetor. Since they were not a military assembly, their meetings were held inside the sacred boundary of the city. They elected minor magistrates, heard criminal appeals above a certain value, and enacted leges (laws) (Thomas 1976:18).  Since there was no weighting by wealth, the plebs had a greater voice here than in the assembly of centuries.  From  449 BC,  the enactments of the comitia tributa could become laws for the entire population if they were sanctioned by the Senate and curies (Sandars 1903;xvii).

With the constitution of the comitia centuriata and the territorial comitia tributa, the plebs became part of populus Romanum and obtained the right to connubium and commercium, although they were at first still prohibited from marriage with patrician families.

With the admission of the plebs to the populus, a new group of patres conscripti was added to the Senate, appointed on the basis of seniority in public service. All Senators were ranked, which determined the order in which they could speak.  The lists of the Senators were originally drawn up by the consuls but came to be drawn up after 443 BC by the censors (Thomas 1976:15).  Censors were elected every five years for a term of 18 months to conduct the Roman census.  Censors were to be men of outstanding integrity, who had already served as consul.   When each census was completed, those who had  completed service in the relevant elected offices would be added to the Senate, but those who had become notorious (for improper conduct) would be expunged. There was no appeal against a decision to expunge.  Nor was such action limited to Senators. By a mark in the roles (nota censoria) the censors could reduce any person in rank and remove them from their tribe.

In domestic matters, the main activity of the Senate was to advise serving officers, using the rigidly standardized form of  senatus consultum.   In foreign affairs, it was supreme. It served as the ultimate supervisory body for conquered territories and appointed sitting or (later) former consuls or praetors to serve as pro-consuls or pro-praetors as governors. It appointed ambassadors and made treaties. Ambassadors from other countries presented themselves to it, not the consuls.  The only check  was that declaring war remained the prerogative of the comitia centuriata alone.

In 493 BC, the plebs demanded greater protection against economic exploitation under cover of law by the patricians. They refused to disband after returning from a military campaign, and threatened to secede.  The outcome was that they received the right to elect tribunes  to defend their interests. (Sandar 1903:xii). Tribunes were elected only by and from the plebs. Initially two, by 449 BC they had increased to ten (Thomas 1976:16). The Tribune had no imperium but could veto (literally “I forbid”) the act of any magistrate (and block the act of another Tribune) and was sacrosanct and inviolable in his person while in office. Lack of an imperium meant that there was no need for confirmation by the comitia curiata, not weakness. On their authority, a person could be arrested, exiled, and have his property confiscated (Havell 1914:49).  In 151 and 138, the tribunes stopped the enrollment of soldiers for unpopular wars in Spain by imprisoning the consuls.

A second major theme in the histories of Roman law is the shift from law that was unwritten to law that was written. The law of the king was unwritten. When the monarchy was overthrown, the ability of the king to say what the law was passed to the college of priests and augers, the pontifs,  whose chief priest, the pontifex maximus, was consulted on law in the trial procedure of the early republic.   But this office was under the control of the patrician curia, and was not considered neutral by the plebs. It was this system that provoked the demand for tribunes, and the tribunes in turn pressed demands for legal reform that produced the foundation of the written law. This was the Twelve Tables, drawn up (not without untoward incident) in 451 and 452 BC, by a committee of ten men, the Decimvirs,  who acted for those years in place of the consuls. The Tables, inscribed on twelve bronze tablets, were thereafter posted at the rostrum at one end of the forum Romanum, the physical and political center of the city. The temple of pontifs was at the other.

Roman scholars customarily praised the Twelve Tables lavishly. Modern scholars frequently observe that they appear to contain no important legal innovations. The importance was in the manner of production. The Decimvirs were both patrician and plebian, and specifically charged with making the law public.  They thus symbolized the idea of a republic— res publica, a public thing — itself.

Additional sources of written law were laws of the comitia tributa, and senatusconsulta, as described, and after 287 BC, plebiscites. Acceptance of plebiscites, legislation originating with the plebian assemblies, as law,  marks the end of the struggle of the orders.  In later centuries, the edicts of the Praetors accumulated and the legal opinions and writings of certain private legal scholars, the  juris consults or juris prudents, were added.  Finally, all were absorbed in the codifications of the Emperors.

The edicts of the praetors developed from the system of election.  A candidate declared the laws he would enforce by an edict, a declaration, that he wrote on a white tablet that would be kept on display during his term.  As time passed, laws that found favor became more and more fixed. Finally, the emperor Hadrian (117?138 AD) ordered the edicts which had become customary for the praetor and aedile to be set down by the jurist Julianus. This became the "Perpetual Edict."

Republican legal scholarship reflected the republican conception of the law as grounded in the authority of the people. The jurisconsults, as they developed in the later republic, were private citizens who served in the capacity of modern lawyers.  Their mode of scholarship, fundamentally akin to that of the Sophists, rested on saying how laws had developed and been interpreted, for what common purposes, and with what effect.
The articulation between constitutional structure and Roman substantive law was the same as it is for us.  The constitutional structure implies a system of rights and prerogatives. Substantive law cannot violate them.  As the constitutional structure makes a major value of protecting established economic interests while preventing the abuse of power by the rich, so must the substantive law. As the constitutional structure provides for access to law and equal treatment under law for all citizens, so must substantive law.

The third great theme in the Roman histories is that the law gradually evolved from being piecemeal and formalistic to being coherent, comprehensive, and flexible. Substantive law consisted of three major bodies that progressively built upon each other: the jus civile, the jus honorarium, and the jus naturalis.

The jus civile began in the monarchy and  lasted until about 180 BC. It was customary and initially unwritten, dealing mainly with family relations, inheritance, marriage, adoption, contract and civil liability. It was originally narrow and formalistic in two senses. The first was that there were rigid rules for making a legally enforceable transaction. Certain very specific words had to be spoken as question and response.  Even this was only valid if it were done on certain days, and neither the formulae nor the days were common knowledge.

To bring a case (legis actione), the practice was to obtain statements of the relevant formulas and rules from the college of the pontifs.  Then, before the magistrate, each party to the suit made a wager, which would be forfeit if they were judged wrong.  The amount wagered would attest to their faith in their cause, cover court costs, and provide a donation to the city cult. Then the magistrate asked each party separately if they had done what the law required and each party responded, also in a highly formalized way.  Then the magistrate instructed a judge (judex), or, for certain kinds of cases, a panel of judges,  what factual circumstances should result in a judgment for either side. The judex was appointed by mutual agreement of both parties from a fixed list of qualified persons . His task was to make the findings of fact and select the option the magistrate directed accordingly. There was at first no conception of mitigation or mutual interdependence of obligations, and many types of actions were simply not provided for. However, it was always a requirement of Roman law that a contract had to be made in accordance with good faith and good morals (bona fides and boni mores).

The jus honorarium grew mainly out of the experience of the praetor perigrinus, and lessened the difference between Roman law and laws of other peoples. To create it, attention shifted from the forms of bringing and defending the suit to the formulae of the instructions that the magistrate gave the judex.  These were expanded and systematized in such a way as to allow more consistency as well as scope to view  obligations as mutually contingent. An important new element was the  exceptio (exception). This could, for example, allow a defendant to admit to having accepted an obligation, but say he had done so because of fraud on the part of the plaintiff (cf. Sandars 1903;lxx).  It also became normal to compose penalties in money (Sandars 1903:lxix).

The lex naturae, according to Cicero, came from the Stoics, mainly Chrysippus (280-209 BC). It was the doctrine that legal results should not be contrary to morality — but then again neither could some magistrate's conception of morality override established law. As Sandars puts it, under this rule:

"The Praetor considered himself bound to arrange his decisions so that no strong moral claims should be disregarded. He had to give effect to the lex naturae not only because it was morally right to do so, but also because the lex naturae was a lex." (Ibid. xxiii).

Lex naturae became increasingly important in the empire, as the republican assemblies were progressively stripped of control over the imperial bureaucracy or abolished.

Roman substantive law distinguished between private law and public law. Private law defined the relationships between one private person and another. Public law defined a person's rights and obligations in relation to the state.  Family and contract law were private law. The laws governing military and political service were public law.

In family law, the central idea of the jus civile was the patria potestas, the power of the father. Within the family, only the patre, the father, was a legal person. Only he was he was sui juris, having an independent will (in law).  In legal terms, his family was based on this power.  While the head was alive, all under his potestas were his closest circle of kin, his agnatio, unless he formally discharged them. For a daughter, this could be done by marriage according to a specific ceremony. A son could be formally released by manumission, a kind of false sale. According to an old law (it was said), a son was free if a father sold him three times. So to release a son, a father would arrange to sell him three times to a non-agnate, and that person could then simply declare him free.

The same procedure for freeing a son from the potestas of the father could be used to transfer a son from one family to another as a form of adoption.  A person sui juris could be adopted by a different procedure, called arrogatio. The next wider circle of kin were the cognati, all those connected to the agnati by ties of blood.  Finally, affines were the cognati of each of the other parties in a marriage (Sandars; xlii). Whether a person was under the potestas of another in private law had no bearing on their relationship in public law.

Contract law was conceived as a system of rights against things and rights against persons – a powerful concept directly related to the way Roman law was both egalitarian and evidentiary. A “right” thus becomes a  possible object for legal attention entirely separate from, for example, the social status or religious position of the person who holds it.  Rights against things were rights in ownership, possession, to use on payment of rent, and to use as a pledge or hypothecation (mortgage). Things were  res mancipi or res nec mancipi.  It appears that the former were things concerning the original agrarian economy, and the latter were others.   Rights against persons were broken down into the right to require a person to give something to another, make something or not make something for another, or to make up a loss.  In all three, such obligations could arise either from consent of the parties (contractus) or from injuries (delicta). Ten forms of consent were recognized, with different rules for each.  Debts incurred were to be made good against the person of the debtor, rather than his property. If the debtor was assessed a penalty and defaulted, he himself was liable to be turned over to the creditors. They could jail him, sell him as a slave, or kill him and divide him according to what was owed.

The law was also careful about what was to be meant by "person.". A person did not have to have physical existence. The state, the fiscus or imperial treasury, and corporations were also persons. A person’s capacity for legal action was determined by its status.  Status had three "constitutive elements:" liberty, citizenship, and membership in a family. Liberty meant whether the person was free or a slave. Citizenship was whether a person was a Roman citizen or an other (varieties of "other" and their legal powers varied over time). Family meant whether a person was sui juris,  under the potestas of another, or under another in any of several other specified capacities.

The republic died under the weight of its success.  With the end of the third Punic war (149-146 BC), the temptations to corruption and exploitation of the conquered areas overpowered the system of public oversight.  Constitutional bodies fell into the hands of radically separate constituencies, each intent on coopting the collective success for themselves. The Senate became the tool of a landed aristocracy of  old patricians and “new men,” self-named the optimates. The tribunate became the weapon of the populares,  the great mass of the poor and of small peasant farmers in Rome and among the Italian allies who had long been denied the  rights and spoils of citizenship, and who were losing land to the senatorial party. And after the reforms of Sulla the equites became a middle class of middling farmers and large financiers who held a distinct interest in controlling provincial tax collection and limiting the oversight of the governors sent out by the Senate.
Civil violence began when the Tribune Gracchus was murdered in 133 BC, by members of the Senate in retaliation for pushing through a reform law that, among other things,  allowed the Latin allies access to conquered lands. It accelerated with each political shift thereafter, leading to the Social War and then the Civil War that ended with Caesar assuming all power. Caesar was elected dictator for ten years in 46 BC and for life in 45 BC. He was assassinated in 44 BC.  “Dictator for life” was a constitutional self-contradiction.

Augustus made Caesar’s consolidation of powers legally palatable. He attained the apex of republican power with his election as consul in 31 BC and was re-elected annually until 23 AD.  When that term expired he declined to run for reelection but had himself given, for life, a pro-consular command superior to other senatorial pro-consuls. (A partial innovation; normally proconsuls could not rule other proconsuls or Rome itself.) He also asked for and received election as a Tribune, although he was a patrician. And in 13 BC  he was also appointed pontifex maximus (the title now borne by the Pope). Thus all the republican offices were preserved, more or less. It was just that they were held by the same person.  This constitutional system was known as the "Principate."

The Principate soon came to be regarded a single office.  Under the "Dominate" established by Diocletian (AD 284-304), it came to be regarded as a hereditary personal estate, the pattern for the hereditary monarchies of Europe. Caesar, Kaiser, and Czar are cognates — from Julius’ and Augustus’ family name..
The empire was ruled by imposition from above in practice as well as theory. Emperors from Diocletian on tried repeatedly to solve problems by  measures such as compelling people to remain in key trades, such as shipbuilding, if they had been born in them under penalty of death.  They legislated prices to control inflation, collected key commodities at sword's point, and made local tax collectors personally liable for shortfalls.

Styles of scholarship changed to reflect the new system. Augustus began the process of transforming the jurisconsults from private scholars to official draftsmen. He appointed certain of them to give responsa (written answers to written questions) with his own authority, although this practice lapsed. Subsequently, Septimius Severus (ruled AD 193?211) paid great attention to legal reform and appointed several famous jurisconsults to important administrative posts. The "classical jurisprudence," more aimed at codification based on logical classification than case by case advice, coalesced at this time.

In 426 AD, the Emperor Valentinian III (419?455) declared that the doctrines of five scholars of the classical jurisprudence were to be followed in deciding cases.  These were Gaius (130?180 AD), Ulpian (died 228 AD), Papinian (140?212 AD), Modestinus (contemporary of Ulpian) and Paulus (flourished C. 212). When emperors began to order codifications of their own, beginning with the Theodosian Code (438 AD), these also rested on the earlier jurisconsults. They were not original legislation but compendia. Contemporary scholars, serving as the emperors' voice, said what the law was by drawing on Aristotelian logic  to rearrange what previous scholars said it had been under the headings of a putatively timeless and universal scheme.

The culmination of imperial codification was Justinian's Corpus Juris Civilis, consisting of three main works completed in final form in 534, AD. The first was the first Code itself, a systematized arrangement of quotations from the classical jurists in twelve books. The second was the  Digest (called Pandects in Greek), arranged in the same manner as the code and intended to "form the necessary base of a legal education" and arrest the declining quality of legal decision making (Sandars 1903:xxxii).  The third was the Institutes, a still more compact summary, in four volumes.

The arrangements are  “logical” and hierarchical.  The first section of the Digest is "Justice and Law" and recounts general definitions of both.  The second is on the origin of law and the different judicial offices, and begins with a quotation from Gaius on the origin of the XII tables. This is followed by a long quotation from Pomponius recounting the development of the Roman legal system through the stages described here. The substantive laws follow in order of  topic and scope.
The Code now extant is the second of two versions, incorporating an intermediate work in which Justinian answered unsettled points. When the first Code had been published,  Justinian ordered all other legal works destroyed and forbade the use of anything else by any judge.  When the final code was published, the first was "carefully suppressed" (Sandars: xxxiv).

Justinian's introduction to the Code added the claim that he was acting "In the Name of Our Lord Jesus Christ,"  and the Code itself  changed traditional Roman family law in favor of Christian recommendations by omitting provisions for divorce and holding that a man and woman joined in marriage were “inseparable” (IX: xxiii.2.1). Concurrently, Aristotelian, neo-Platonic and Stoic ideas were being adopted in the Church as the basis of  systematic theology. Thus the Roman Empire converted itself to what was to become the various forms of the Holy Roman Empire and the Church Hellenized itself to meet it.

Justinian evidently assumed that once the law was fixed into a consistent logical form and everything else obliterated, it would remain stable thereafter. Few predictions have been more wrong.  The empire split in his lifetime and the western half was lost.  Procopius, his general, was quite direct about the reasons. It was the result of alienation and disaffection that flowed from the central characteristic of the system itself: as sole voice and source of the law, there was nothing to prevent the Emperor from abusing the law. Law became force. He characterizes Justinian as a "destroyer" who, among other things,  "devoured all the public moneys and robbed each member of the Senate, publicly and privately, of all estates; and  . . . by bringing false charges he confiscated the  properties of every one else who was reputed to be wealthy (Atwater 1927;242).

In the Eastern Empire, Justinian's corpus was soon known only by Greek paraphrases and abridgments. In the western Empire, effective law came to be that of the Germanic tribes, as represented by the Visigothic and Burgundian codes. These were based on pre-Justinian Roman models and served a double purpose.  They set down their own traditional laws in a newly public and systematic form, and they coordinated these laws with those of the Roman settlements the German rulers took under their protection (cf. Drew 1972:6-10).

The scholars of the republic had persistently praised its law for its ability to attract the loyalty of its citizens by aligning their personal interests with the preservation of public institutions — integration from below. The scholars of the empire reversed the principle and attributed stability to the submission to authority from above. Modern pragmatic and positivistic arguments are built on the same patterns.