What is Laws Of The Twelve Tables?

Legal Definition
Laws of ancient Rome composed in part from those of Solon, and other Greek legislators, and in part from the unwritten laws or customs of the Romans. These laws first appeared in the year of Rome 303, inscribed on ten plates of brass. The following year two others were added, and the entire code bore the name of the Laws of the Twelve Tables. The principles they contained became the source of all the Roman law, and serve to this day as the foundation of the jurisprudence of the greatest part of Europe.

See a fragment of the Law of the twelve Tables in Coop. Justinian, 656; Gibbon's Rome, c. 44.
-- Bouviers Law Dictionary