Lex talionis is a legal principle that translates to 'the law of retaliation,' often expressed as 'an eye for an eye, a tooth for a tooth.' This concept emerged prominently in ancient legal systems, particularly in the context of Mesopotamian city-states and early empires, where it served as a guideline for justice and retribution. The principle aimed to establish proportionality in punishment and played a significant role in shaping societal norms regarding justice and morality in ancient cultures.