The distribution of the inherited wealth has varied greatly among different cultures and legal traditions. In nations using civil law, for example, the right of children to inherit wealth from parents in pre-defined ratios is enshrined in law, as far back as the Code of Hammurabi (ca. 1750 BC). In the US State of Louisiana, the only US state where the legal system is derived from the Napoleonic Code, this system is known as "forced heirship" which prohibits disinheritance of adult children except for a few narrowly-defined reasons that a parent is obligated to prove. Other legal traditions, particularly in nations using common law, allow inheritances to be divided however one wishes, or to disinherit any child for any reason.