When litigants wish to settle their dispute among themselves, even while they are on their way to appear before the Prætor, they shall have the right to make peace; and whatever agreement they enter into, it shall be considered just, and shall be confirmed.

-The Twelve Tables, Tablet I, Law VII

This law from the Twelve Tables, the a fifth-century BCE compilation comprising the oldest code of Roman law, codifies the principal of encouraging mediation and settlement between litigants in ancient Roman Law. The Twelve Tables formed much of the basis of ancient Roman law through the various leges and iura of the middle and late Republic and the several codices of the Imperial period (most famously the 6th century Code of Justinian).

The principles of Roman law were incorporated into church canon law as well as the civil law codes of medieval Europe.  They were enormously influential in the development of English common law and therefore form part of the underpinnings of modern Anglo-American jurisprudence.

For more information, see Hans Julius Wolff, Roman Law: An Historical Introduction (Univ. of Oklahoma Press, 1976); Barry Nicholas and Ernest Metzger, An Introduction to Roman Law (Oxford Univ. Press, 1976); Andrew Riggsby, Roman Law and the Legal World of the Romans (Cambridge Univ. Press, 2010).