The Timpson Lyceum · History of Rome – Titus Livius (2025)

The Decemviri & 12 Tables of Roman Law – Lecture 14 (History of Rome)

Overview

By the 450s BC the plebeians had a sharper grievance than any single law: Roman law itself was unwritten. With no published statutes, "law" and mere "custom" blurred together, and patrician magistrates could interpret both to their own advantage. The plebeian answer, pressed for years through the Lex Terentilia, was to force Rome's rules into fixed, public writing. After long resistance, distraction (the Aventine granted to the plebs), and even an embassy to Athens to study the laws of Solon, the orders struck a bargain: suspend the normal magistracies and appoint a board of ten men — the decemviri — to codify all Roman law.

The result was the Twelve Tables (451–450 BC), Rome's first written code and the foundation of all later Roman law. But the story is also a cautionary tale about unchecked power. The first decemvirate governed superbly; the second, dominated by Appius Claudius, turned tyrannical, ruling without appeal until the judicial murder of the girl Verginia provoked the Second Secession of the Plebs and toppled the board. The episode fixed two Roman convictions at once: that law must be public and equal, and that no magistracy may stand beyond appeal.

Key Concepts

• Unwritten law — Before the Twelve Tables, Roman law was oral and customary; no citizen could consult a text, so patrician magistrates effectively decided what the law was case by case. Codification was the plebs' remedy.
• Lex Terentilia — The proposal (by the tribune Terentilius) to appoint a commission to put the consular powers in writing and limit them. Patricians resisted, fearing it would tie magistrates' hands with technicalities.
• Lex Icilia (Aventine to the plebs, 456 BC) — A law reserving the Aventine Hill for plebeian settlement, offered partly to placate the plebs while the larger codification fight continued.
• Embassy to Athens — Three envoys were sent to Greece to study the laws of Solon and other Greek constitutions, since Athens had earlier navigated a similar crisis of concentrated landholding and popular discontent.
• The compromise — Rather than merely limiting consular power, the orders agreed to write down all law and display it publicly; patricians accepted on the condition that the codifiers be patricians, and plebs on the condition that no existing plebeian gains be repealed.
• The Decemvirate (451 BC) — A board of ten men granted the combined powers of consuls, tribunes, and judges, with the normal magistracies suspended and no appeal against their rulings; only one held the fasces each day, rotating daily. Led in prestige by Appius Claudius, the first board ruled justly and produced ten Tables of law, circulated for public feedback.
• The second Decemvirate (450 BC) — Reappointed to finish the code, it added two more Tables to make twelve. Appius Claudius rigged the elections to install his allies, and the board turned tyrannical — all ten now parading with fasces and axes, claiming that because there was no appeal from them, acting as dictators was no abuse.
• Lucius Siccius Dentatus — A veteran and vocal plebeian critic sent out on a pretext and murdered by a scouting party on the decemvirs' orders — an assassination that enraged the army facing the Sabines.
• Verginia — The daughter of the centurion Verginius and betrothed of the former tribune Icilius. Appius Claudius, unable to seduce her, had his client Marcus Claudius claim her as a runaway slave; judging his own case, Appius awarded her to Marcus. To save her from bondage, Verginius stabbed his daughter dead in the Forum.
• Second Secession of the Plebs — Following Verginia's death, the two field armies marched armed into Rome and then withdrew to the Sacred Mount and the Aventine, refusing to serve until the decemvirate fell.
• Fall of the decemvirate — The decemvirs resigned on the condition of protection; the plebs recovered their tribunes and the right of appeal. Valerius and Horatius became consuls and Verginius and Icilius tribunes.
• The Valerio-Horatian Laws — A package restoring and strengthening plebeian rights: tribunes made sacrosanct, the right of appeal reaffirmed (no magistracy may be created without it), and Senate decrees (senatus consulta) required to be archived with the plebeian aediles.
• Sample provisions of the Twelve Tables — Concrete, everyday rules: fruit falling onto a neighbor's land belongs to the neighbor; a cap of 100% interest on loans; and the strict law of debt and lex talionis (retaliation) described below.

Worked Example

Formalizing the Twelve Tables as structured rules. The code's power lay in converting vague custom into definite, applicable rules. Two features illustrate this: the arithmetic of the code itself, and the logical form of a single provision.

1. The size of the code. The first board produced ten Tables and the second added two:

$10 + 2 = 12 \text{ Tables.}$

Each Table bundled several clauses, so twelve Tables held dozens of enforceable rules — small enough that Roman schoolboys later memorized them entire.

1. State a provision as a conditional. Take the famous law of retaliation, "si membrum rupsit, ni cum eo pacit, talio esto" — "if a man breaks another's limb, and does not settle with him, let there be retaliation." As a logical rule with an ordered escape hatch:

$\big(\text{limb broken}\big)\ \wedge\ \neg\big(\text{settlement reached}\big)\ \Rightarrow\ \text{talio (like-for-like penalty)}.$

The clause $\neg(\text{settlement})$ shows the law preferred private compromise; retaliation applied only when negotiation failed.

1. Apply the debt law as a timed procedure. Table III turned default into a fixed sequence of deadlines rather than an arbitrary seizure. After a judgment for a sum owed:

   • Step 1 — a grace period of $30$ days to pay.
   • Step 2 — if unpaid, the creditor could seize the debtor (manus iniectio) and hold him for $60$ days, producing him publicly on three successive market days (nundinae).
   • Step 3 — still unpaid, the debtor could be sold into bondage across the Tiber.

2. Compute the timeline to bondage. The total protected interval before enslavement was:

$30 + 60 = 90 \text{ days.}$

With Roman market days recurring every eight days, the three required public presentations spanned roughly $2 \times 8 = 16$ days within that window — three chances, in public, for family or friends to intervene and pay.

1. Interpret. The value of writing the law down is exactly this determinacy: a debtor and creditor could both count the days. Power passed from a magistrate's discretion to a published, countable rule — the whole point of the Twelve Tables. $\blacksquare$

Summary

• The plebs' core grievance was that Roman law was unwritten; codification promised equal, public rules in place of patrician discretion.
• After the Lex Terentilia fight, the Aventine concession, and an embassy to study Solon's laws, the orders appointed the decemviri, suspending normal magistracies to write the code.
• The first decemvirate (451 BC) governed well and produced ten Tables; the second (450 BC) added two more for twelve total but, under Appius Claudius, ruled tyrannically and without appeal.
• The judicial murder of Verginia triggered the Second Secession of the Plebs, which brought down the decemvirate and restored the tribunate and the right of appeal.
• The Twelve Tables became the bedrock of Roman law — from lex talionis to the timed law of debt — and the crisis entrenched the principle that no magistracy may stand above appeal.