Nobility is a historical, social and often legal notion, which should not be confused with socio-economic status which is mainly statistical based on income and possessions. Being wealthy or influential does not automatically make one a noble, nor are all nobles wealthy and influential (aristocratic families have lost their fortunes in various ways, and the concept of the 'poor nobleman' is almost as old as nobility itself).
Countries without a feudal tradition do not have a nobility as such. Various republics, including the United States and Italy have expressly abolished titles of nobility. Although many such societies have a privileged 'upper class' with great wealth and power, this does not entail a separate legal status, or different forms of address.
The nobility of a person might be either inherited or earned. Nobility in its most general and strict sense is an acknowledged preeminence that is hereditary: i.e., legitimate descendants (or all male descendants, in some societies) of nobles are nobles, unless explicitly stripped of the privilege. In this respect, nobility is distinguished from the peerage: the latter can be passed to only a single member of the family. The terms aristocrat and aristocracy are a less formal means to refer to persons belonging to this social milieu. Those lacking a distinct title, such as junior siblings of peers (and perhaps even the children of 'self-made' VIPs) may be considered aristocrats, moving within a small social circle at the apex of a hierarchical social pyramid.
Robert Lacey explains the genesis of the blue blood concept:
It was the Spaniards who gave the world the notion that an aristocrat's blood is not red but blue. The Spanish nobility started taking shape around the ninth century in classic military fashion, occupying land as warriors on horseback. They were to continue the process for more than five hundred years, clawing back sections of the peninsula from its Moorish occupiers, and a nobleman demonstrated his pedigree by holding up his sword arm to display the filigree of blue-blooded veins beneath his pale skin—proof that his birth had not been contaminated by the dark-skinned enemy. (Robert Lacey, Aristocrats. Little, Brown and Company, 1983, p. 67)
The same expression is encountered in other languages:
|Albanian||gjak i kaltër (djak i kalteur)||Bulgarian||синя кръв (sinya krăv)||Catalan||sang blava|
|Czech||modrá krev||Croatian||plava krv||Danish||blåt blod|
|Dutch||blauw bloed||Estonian||sinivereline||French||sang bleu|
|Filipino/Tagalog||dugong bughaw||Finnish||siniverisyys||German||blaues Blut|
|Greek||γαλαζοαίματος (galazoaímatos)||Hungarian||kékvérű||Icelandic||blátt blóð|
|Italian||sangue blu||Lithuanian||mėlynas kraujas||Macedonian||сина крв|
|Maltese||demm blu||Norwegian||blått blod or blåblodig||Persian||Najabat or نجابت|
|Polish||błękitna krew||Portuguese||sangue azul||Romanian||sânge albastru|
|Russian||голубая кровь (golubaya krov’)||Serbian||плава крв (plava krv)||Slovak||modrá krv|
|Slovenian||modra kri||Spanish||sangre azul||Swedish||blått blod or blåblodig|
In France, influential high bourgeois, most particularly the members of the parlements (courts of justice), obtained noble titles from the king. The old nobility of military origin, the noblesse d'épée ("nobility of the sword") became increasingly irritated by this newer noblesse de robe ("nobility of the gown"). In the last years of the ancien régime, before the French Revolution, the old nobility, intent on keeping its privileges, had pushed for restrictions of certain offices and orders of chivalry to noblemen who could demonstrate that their family had enough "noble quarterings" (in French, 'quartiers de noblesse'), a reference to a noble's ability to display armorially their descents from armigerous noble forebears in each of their lines of descent to demonstrate that they were descended from old noble families, who bore arms that could be quartered with their own male line arms, and thus prove that they did not derive merely from bourgeois families recently elevated to noble rank (although historians such as William Doyle have disputed this so-called 'Aristocratic Reaction'. (W. Doyle, Essays on Eighteenth Century France, London, 1995). A noble could be asked to provide proof of noble antecedents by showing a genealogy displaying seize quartiers (sixteen quarterings) or even trente-deux quartiers (thirty-two quartering) indicating noble descent on all bloodlines back five generations (to great-great grandparents) or six generations (great-great-great grandparents), respectively. This illustrates the traditional link in many countries between heraldry and nobility; in those countries where heraldry is used, nobles have almost always been armigerous, and have used heraldry to demonstrate their ancestry and family history. (However, it is important to note that heraldry has never been restricted to the noble classes in most countries, and being armigerous does not necessarily demonstrate nobility.)
Nobles typically commanded resources, such as food, money, or labor, from common members or nobles of lower rank of their societies, and could exercise religious or political power over them. Also, typically, but not necessarily, nobles were entitled to land property, which was often reflected in the title. For example, the title Earl of Chesterfield tells about property, while the title Earl Cairns was created for a surname. However all the above is not universal; quite often nobility was associated only with social respect and certain social privileges. An example of the latter would be early 20th-century Polish nobility (szlachta) after their political, economic, judicial and religious privileges were abolished in 1921 and they remained only landed proprietors on the same legal basis as their landed-commoner neighbours. In the modern age, the notion of inherited nobility with special rights has become, in the Western World, increasingly seen as irrelevant to the modern way of life. The founding fathers of the United States rejected anything that could have helped in recreating a nobility; the French Revolution abolished the nobility and its special privileges (though some nobility titles would be recreated by Napoleon I and III, they were mostly honorific).
Some con artists also sell fake titles of nobility, often with impressive-looking documents to back them up. These may be illegal, depending on local law. They are more often illegal in countries that actually have nobilities:such as European monarchies. In the U.S., such commerce would be a form of fraud, but it would only victimize the buyer of the supposed titles and would not threaten an established class of nobles with enforceable titles.
Many other non-Western nations have had noble or aristocratic classes of various kinds: these are so diverse that it is somewhat misleading to try to translate them all into western feudal terminology. For the feudal hierarchy on the Indian subcontinent, see princely state.
In some Islamic countries, there are no definite nobility titles, but the closest to that are given the title Syed or Sayyid. This exclusive title, given only to certain descendants, literally means, 'Sir' or 'Lord'. There are no special rights concerning the title: they are considered more religious than the general population, and many people come to them for first-hand religious questions.
In Iran, the nobility titles are Mirza, Khan, ed-Dowleh, Shahzada, etc... . Nowadays, these titles don't exist anymore, an aristocrat family can now being recognized by his family name (often derived from the post the ancestors had, considering the fact that family name in Iran only appeared in the beginning of the 20th century) .
In East Asia the system was often modelled on imperial China, the leading culture, where the emperor conferred degrees of nobility, which were not permanent but decreased a rank each generation. China had a feudal system in the Shang and Zhou dynasties, but the system gave way to a more bureaucratic system beginning in the Qin dynasty (221 BC). By the Qing dynasty, titles of nobility were still granted by the emperor, but served merely as honorifics: under a centralized system, governance in the empire was the responsibility of the Confucian-educated scholar-officials and local gentry.
In tribal societies, such as and the Polynesian Island states, the system of often (semi-)hereditary tribal chiefs can also be compared to a form of noble class; in Tonga, after Tongan contact with Western nations, the traditional system of chiefs developed into a Western-style monarchy with a hereditary class of barons, even adopting that English title.