In a broad sense, the term law includes the law itself, plebiscites and senatus consultum.


Rome did not know the system of separation of powers. However, the people, the Senate and the magistrates exercised legislative power so regular and discreet so that he could keep a constant balance between them throughout the Republican period.

At first was for senior judges propose laws, which were written in their own homes (scriptio legis) using individuals versed in the ancient usages and customs (mores maiorum).

Written law, the text was transferred to the Senate: without prior leave of the Senate could not summon the elections, as in practice often reluctant to grant that permission, in 338 BC the Senate was forced to approve laws that would have to vote in comitia centuriata (leges Publilia de legibus and Maenia de comitibus).

If the Senate approved, the project received a favorable opinion through a senatus consultum, which significantly enhanced their chances of success in the vote; but if he did compelled by the orders of the Publilia and Maenia laws, simply said that he enjoyed the authorization of the Fathers (auctoribus patribus) pronouncement less commitment than a senatus consultum.

Then it was exposed for examination for about 27 days (trinundinum) so that citizens could attend formed to review the elections that were to approve or reject.

The assembly gathered in the Champ de Mars or in the comitium, a crier recited the project and who had proposed (auctor legis) delivered a eulogy speech and advised the adoption of the new law (suadere legem). Then, the proposal could be defended or rejected by the other magistrates (this power was inherent in his position) or by any individual who has been authorized to speak (disuadere legem).

As they finished the sacred rites, it could disrupt the vote at the request of the tribunes of the plebs, the Consul (disabling the day) and Augures and certain judges, announcing evil omens observed in the sky.

If not mediate any of these obstacles, began the vote in the order of tribes or centuries that followed from the raffle than previously realized.

The votes were given orally, until tabularias laws forced to do it through tablets on which were marked with the letters U.R. (uti rogas) to approve and A (antiquo) to refuse.

Once voting they proceeded to count the votes in each century and then another scrutiny of global vote of the centuries, after which came definitely taken the law (scita et perlata) or discarded (antiquata). It was confirmed with an oath, the Senate approved and sculpted in bronze foil was deposited in the treasury (sometimes were recorded in columns in public places). The law took the name of the Consuls under whose auspices were established and, sometimes, of the magistrate that proposed, followed by a reference to its content.


They were proposed by the plebeian magistrates. Unlike laws:
        • no previous rites of stargazing, consult omens or authorization of Patres were required.
        • were prayed by plebeian magistrates.
        • were discussed at the Campus Martius, the Forum, the Circus Flaminius and even at the Capitol.
        • draw formalities were different (there were one to know in what tribe were the Latinos aggregated and other to determine the order of suffrage of all tribes).
        • bronze tablet with the approved text is kept in a temple in the custody of the aediles plebis.
        • not begging for tribes or centuries, but only by tribes.
        • the vote came only the plebs, without prejudice to the provisions thus adopted were mandatory for all state orders.


The Senate, originally conceived as an advisory board serving the consuls (consilium reipublicae sempiternum), became an executive institution completely independent, since it had reserved the functions of consular control, supervision of the army and policy direction outside.

Contrary to popular belief and even in some cases could promote laws, was not really a legislative chamber: usually, the Roman laws were promoted by the tribunes of the plebs and sanctioned directly by the people, after consulting the Senate (senatus consultum).

Under the rule of the Caesars the influence of the Senate, which concentrated all legislative power, was increased (however, this concentration of legislative power existed only in appearance, because the Senate become a mere instrument in the service of the emperors).

The senatus consultum was one of the main sources of Roman law: if during the Republic had considered simple advisory opinion given by the Senate to a magistrate, under the Empire, became a binding act with force of law (senatus consultum est quod senatus iubet atque constituit; idque legis vicem optinet, quamvis fuerit quaesitum). The senate always decided on issues of common or general interest, unlike the decree of the Senate, which only gave response to issues of particular interest.

In senatus consultum apeared the date and place; after, the name of all attendees senators; then the proposal and the name of the magistrate who had presented it and finally the approved text:

Senatus consulti auctoritas
pridie kal. octob. in sede apollinis
scribendo adfuerunt L. Domitius P. Canuleius, ...
quod M. Aemilius eis verba fecit de ...
de ea re ita consuerunt ut, ...

The passage of laws by the Senate was not mandatory but essential therefore to have executive power, the Senate could help or hinder the implementation of an approved plebiscit, so that any tribune who wanted to see properly developed program saw the need to reach agreement with the Senate. In urgent cases, which usually appear in the context of war or crisis, the Senate could legislate without laws were ratified by the Assembly, subject to ratification, that by the end of the Republic it was almost never requested.

The Senate held its regular sessions the Kalends, Nones and Ides (from Augustus, only the Kalends and the Ides), while the non regular could take place any day provided that there were no comitia. Always mediated the previous call, which was made orally by a preacher or individually to senators who lived outside the walls. The call was directed not only to senators, but also others who, without being, had seat and vote for serving or have served any magistracy.

When the day appointed for the meeting and completed the rites and formalities which must be observed if the auspices were favorable and there was no opposition from a magistrate of equal or higher rank, senators occupied the seats according to their rank and began the session.

Took the floor proponent to expose and defend their approval (relatio), after opening the discussion as speaking time following the same order of preference established for the seats. After talking each other, they proceeded to the voting formula qui hoc sentitis illuc transit, qui alia omnia in hanc partem and then count the senators placed on both sides of the chamber to hear the decision of the Senate.

After the counting and known Patres resolution, the senatus consultum was written, which ended with the agreed decision always after the formula D.E..R.I.C. (de ea re ita consuerunt).

As the tribunes of the plebs could resist the execution, was added at the end of the formula si quis huic senatusconsulto intercesserit, senatui placere, auctoritatem perscribi, et de ea re ad senatum populumque referri.

If the opposition had already been formulated, the tribune veto (intercessio) was made with this formula: huic senatusconsulto intercessit ... Tribunus plebis, in which case the decision reached not have the status of senatus consultum and was called only authority of the Senate.

If the tribunes approved the agreement, the Senate took the letter T in acquiescence. After was published (except those requiring strict secrecy) and finally the tablet was deposited in the temple of Ceres in the custody of the aediles plebis or under Augustus, in the treasury in charge of urban quaestors.

The senatus consultum took the name of the magistrate that suggested it, they did not have the character of laws and they were in force only during the year of office of the magistrate who had promoted them.

In times of Tiberius, under the pretext of the difficulty of bringing such a large population, the emperor moved to the Senate the legislative power of the comitia and stated that its decisions can not be forced until be confirmed by an edict of the emperor.