Et quidem initio civitatis nostrae populus sine lege certa, sine iure certo primum agere instituit omniaque manu a regibus gubernabantur. postea aucta ad aliquem modum civitate ipsum Romulum traditur populum in triginta partes divisisse, quas partes curias appellavit propterea quod tunc reipublicae curam per sententias partium earum expediebat. et ita leges quasdam et ipse curiatas ad populum tulit: tulerunt et sequentes reges. quae omnes conscriptae exstant in libro sexti Papirii, qui fuit illis temporibus, quibus superbus Demarati Corinthii filius, ex principalibus viris. is liber, ut diximus, appellatur ius civile Papirianum, non quia Papirius de suo quicquam ibi adiecit, sed quod leges sine ordine latas in unum composuit. exactis deinde regibus lege tribunicia omnes leges hae exoleverunt iterumque coepit populus Romanus incerto magis iure et consuetudine aliqua uti quam per latam legem, idque prope viginti annis passus est. postea ne diutius hoc fieret, placuit publica auctoritate decem constitui viros, per quos peterentur leges a Graecis civitatibus et civitas fundaretur legibus: quas in tabulas eboreas perscriptas pro rostris composuerunt, ut possint leges apertius percipi: datumque est eis ius eo anno in civitate summum, uti leges et corrigerent, si opus esset, et interpretarentur neque provocatio ab eis sicut a reliquis magistratibus fieret. qui ipsi animadverterunt aliquid deesse istis primis legibus ideoque sequenti anno alias duas ad easdem tabulas adiecerunt: et ita ex accedenti appellatae sunt leges duodecim tabularum. quarum ferendarum auctorem fuisse decemviris Hermodorum quendam Ephesium exulantem in Italia quidam rettulerunt.
(Pomponius, Encheiridion fr. 178 Lenel (partim) = Digesta 18.104.22.168-4)
The fact is that at the outset of our civitas, the citizen body decided to conduct its affairs without fixed statute law or determinate legal rights; everything was governed by the kings under their own hand. When the civitas subsequently grew to a reasonable size, then Romulus himself, according to the tradition, divided the citizen body into thirty parts, and called them curiae on the ground that he improved his curatorship of the commonwealth through the advice of these parts. And accordingly, he himself enacted for the people a number of statutes passed by advice of the curiae [leges curiatae]; his successor kings legislated likewise. All these statutes have survived written down in the book by Sextus Papirius, who was a contemporary of Superbus, son of Demeratus the Corinthian, and was one of the leading men of his time. That book, as we said, is called The Papirian Civil Law, not because Papirius put a word of his own in it, but because he compiled in unitary form laws passed piecemeal. Then, when the kings were thrown out under a Tribunician enactment, these statutes all fell too, and for a second time, the Roman people set about working with vague ideas of right and with customs of a sort rather than with legislation, and they put up with that for nearly twenty years. After that, to put an end to this state of affairs, it was decided that there be appointed, on the authority of the people, a commission of ten men by whom were to be studied the laws of the Greek city states and by whom their own city was to be endowed with laws. They wrote out the laws in full on ivory tablets and put the tablets together in front of the rostra, to make the laws all the more open to inspection. They were given during that year sovereign right in the civitas, to enable them to correct the laws, if there should be a need for that, and to interpret them without liability to any appeal such as lay from the rest of the magistracy. They themselves discovered a deficiency in that first batch of laws, and accordingly, they added two tablets to the original set. It was from this addition that the laws of the Twelve Tables got their name. Some writers have reported that the man behind the enactment of these laws by the Ten Men was one Hermodorus from Ephesus, who was then in exile in Italy. (tr. Alan Watson)