n. 1) any system of regulations to govern the conduct of the people of a community, society or nation, in response to the need for regularity, consistency and justice based upon collective human experience. Custom or conduct governed by the force of the local king were replaced by laws almost as soon as man learned to write. The earliest lawbook was written about 2100 B.C. for Ur-Nammu, king of Ur, a Middle Eastern city-state. Within three centuries Hammurabi, king of Babylonia, had enumerated laws of private conduct, business and legal precedents, of which 282 articles have survived. The term "eye for an eye" (or the equivalent value) is found there, as is drowning as punishment for adultery by a wife (while a husband could have slave concubines), and unequal treatment of the rich and the poor was codified here first. It took another thousand years before written law codes developed among the Greek city-states (particularly Athens) and Israel. China developed similar rules of conduct, as did Egypt. The first law system which has a direct influence on the American legal system was the codification of all classic law ordered by the Roman Emperor Justinian in 528 and completed by 534, becoming the law of the Roman empire. This is known as the Justinian Code, upon which most of the legal systems of most European nations are based to this day. The principal source of American law is the common law, which had its roots about the same time as Justinian, among Angles, Britons and later Saxons in Britain. William the Conqueror arrived in 1066 and combined the best of this Anglo-Saxon law with Norman law, which resulted in the English common law, much of which was by custom and precedent rather than by written code. The American colonies followed the English Common Law with minor variations, and the four-volume Commentaries on the Laws of England by Sir William Blackstone (completed in 1769) was the legal "bible" for all American frontier lawyers and influenced the development of state codes of law. To a great extent common law has been replaced by written statutes, and a gigantic body of such statutes have been enacted by federal and state legislatures supposedly in response to the greater complexity of modern life. 2) n. a statute, ordinance or regulation enacted by the legislative branch of a government and signed into law, or in some nations created by decree without any democratic process. This is distinguished from "natural law," which is not based on statute, but on alleged common understanding of what is right and proper (often based on moral and religious precepts as well as common understanding of fairness and justice). 3) n. a generic term for any body of regulations for conduct, including specialized rules (military law), moral conduct under various religions and for organizations, usually called "bylaws."