Elsewhere I have defined nobility law as “national legislation, or international or national customs, that regulate nobility issues. In many cases this is not codified, but rather a set of rules and traditions that have gained acceptance” (see my book in http://www.findyournobleancestors.com).
Examples of some of the most important issues regulated by noble law are:
– Claims of nobility (surname, coat of arms, title) of non-noble people. This could, but should not, include: children with one or two noble parents but born out of wedlock; stepchildren of noble parents; children to a noble lady in an agnatic family, etc.
– Claims of nobility by noble persons, when claims cannot be verified automatically. This could be, for example, the inheritance of a noble title in a lower line of the family when the upper line is extinguished.
– Borderline cases, such as those that between the old patrician families should and should not be counted among the nobility. Or the revival of a family’s nobility after some time of voluntary or involuntary loss of nobility (usually because one or all of the noble qualities have not been used for two or more generations).
– the naturalization of the foreign nobility, that is, the assimilation of the immigrant nobility to the national nobility, generally in order to guarantee the foreign nobility the same privileges as the national nobility.
– heraldry, and more specifically the use of certain symbols usually reserved for the nobility, such as crowns of noble rank, the use of sympathizers, etc. Also the classification of arms, which is the appropriate combination of two or more coats of arms due to marriage between two noble families, and similar issues may be regulated.
In some countries nobility is a matter of public law (Belgium, Finland, the Netherlands and in Spain only with regard to titled nobility). In other countries this is not the case, and then the nobility may have organized into one or more associations in order to have an institution to handle noble issues such as those mentioned above. Therefore, it is of utmost importance for each noble family to define and clarify under what legislation, or under what set of rules or regulations, whether they are codified or not, they are an issue.
Nobility law is a complex and multifaceted subject. Extensive research is often necessary to establish which rules apply to a specific noble family. A starting point may be to collect relevant literature from (or about) the country where the family is known (or believed) to have been ennobled (or first recognized as noble). This can be done by searching the many antiquarian bookstores available on the Internet for keywords such as “nobility” or “nobleman” in the title of the book. Sometimes a specific internet site will be dedicated to noble law (such as Italian http://www.dirittonobiliare.com).
Perhaps the most important thing to remember about noble law is that it is not the same as public law. It is quite possible, according to national legislation, that a non-noble person assumes a noble surname, but this does not make them members of the nobility. A person can only be a member of the nobility if he is in accordance with noble law, whether or not he is in harmony with public law.