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Ancient Sumer's Code of Ur-Nammu was compiled circa 2100-2050 BC, and is the earliest known surviving civil code. Three centuries later, the Babylonian king Hammurabi enacted the set of laws named after him.
Besides religious laws such as the Torah, important codifications were developed in the ancient Roman Empire, with the compilations of the Lex Duodecim Tabularum and much later the Corpus Iuris Civilis. These codified laws were the exceptions rather than the rule, however, as during much of ancient times Roman laws were left mostly uncodified.
The first permanent system of codified laws could be found in China, with the compilation of the Tang Code in AD 624. This formed the basis of the Chinese criminal code, which was then replaced by the Great Qing Legal Code, which was in turn abolished in 1912 following the Xinhai Revolution and the establishment of the Republic of China. The new laws of the Republic of China were inspired by the German codified work, the Bürgerliches Gesetzbuch. A very influential example in Europe was the French Napoleonic code of 1804.
Another early system of laws is Hindu law framed by Manu and called as Manu Smriti, dating back to the 2nd century BC. The use of civil codes in Islamic Sharia law began with the Ottoman Empire in the 19th century AD.
Codification in common law and civil law jurisdictions 
Contrary to popular belief, the common law has been codified in many jurisdictions in many areas; examples include the Law of General Obligations of New York State, the English law relating to marine insurance in the Marine Insurance Act 1906, which was originally judge-made common law, and the California Civil Code.
In civil law jurisdictions, codification has also occurred in many areas. Statutes of the Grand Duchy of Lithuania were most notable codifications of law in the Central and Eastern Europe of the 16th century. The codification movement developed out of the philosophy of the Enlightenment and began in several European countries during the late 18th century (see civil code). However, it only gained significant momentum with the enactment of the French Napoleonic Code in 1804.
Codification in the United States 
In the United States, acts of Congress, such as federal statutes, are published chronologically in the order in which they become law — often by being signed by the President, on an individual basis in official pamphlets called "slip laws," and are grouped together in official bound book form, also chronologically, as "session laws." The "session law" publication for Federal statutes is called the United States Statutes at Large. Any given act may be only one page, or hundreds of pages, in length. An act may be classified as either a "Public Law" or a "Private Law."
Because each Congressional act may contain laws on a variety of topics, many acts, or portions thereof are also rearranged and published in a topical, subject matter codification. The official codification of Federal statutes is called the United States Code. Generally, only "Public Laws" are codified. The United States Code is divided into "titles" (based on overall topics) numbered 1 through 51. Title 18, for example, contains many of the Federal criminal statutes. Title 26 is the Internal Revenue Code.
Even in code form, however, many statutes by their nature pertain to more than one topic. For example, the statute making tax evasion a felony pertains to both criminal law and tax law, but is found only in the Internal Revenue Code. Other statutes pertaining to taxation are found not in the Internal Revenue Code but instead, for example, in the Bankruptcy Code in Title 11 of the United States Code, or the Judiciary Code in Title 28. Another example is that the national minimum drinking age, not logically found in Title 27, Intoxicating liquors, but in Title 23, Highways, §158.
Further, portions of some Congressional acts, such as the provisions for the effective dates of amendments to codified laws, are themselves not codified at all. These statutes may be found by referring to the acts as published in "slip law" and "session law" form. However, commercial publications that specialize in legal materials often arrange and print the uncodified statutes with the codes to which they pertain.
In the United States, the individual states, either officially or through private commercial publishers, generally follow the same three-part model for the publication of their own statutes: slip law, session law, and codification.
In international law 
Following the First World War and the establishment of the League of Nations, the need for codification of international law arose. In September 1924, the General Assembly of the League established a committee of experts for the purpose of codification of international law, which was defined by the Assembly as consisting of two aspects:
- Putting existing customs into written international agreements
- Developing further rules
In 1930 the League of Nations held at the Hague a conference for the purpose of codification of rules on general matters, but very little progress was made.
Following the Second World War, the International Law Commission was established within the United Nations as a permanent body for the formulation of principles in international law.
Recodification refers to a process where existing codified statutes are reformatted and rewritten into a new codified structure. This is often necessary as, over time, the legislative process of amending statutes and the legal process of construing statutes by nature over time results in a code that contains archaic terms, superseded text, and redundant or conflicting statutes. Due to the size of a typical government code, the legislative process of recodification of a code can often take a decade or longer.