Why are nobles said to have blue blood? The historical meaning of the expression

Have you ever heard the expression “have blue blood”? It is a way of saying whose origins date back to medieval Spain and is used to indicate or describe the nobility, whose bluish appearance of veins visible beneath pale skin was once a hallmark of those who could afford not to work outdoors. Although it may seem like simple folklore, this phrase contains a mixture of biological, social and economic meanings that have marked class distinctions throughout the centuries.

Origins and evolution of the expression

The origin of the phrase “blue blood”, according to the British historian Robert Lacey, it goes back to Spain of the Middle Ages, a period in which class distinction (nobility, clergy, fat and small city people and serfs) was very evident and visually accentuated by skin color.

THE noblesnot working under the sun, they maintained a complexion noticeably clearer compared to farmers or low-class workers, constantly exposed to the open air (hence also the expression “noble pallor”). This difference resulted in veins more visible and of a bluish color under the translucent skin, which they boasted of as a demonstration of the privilege of not having to work, in stark contrast to the skin darkened by fatigue and the sun of the working class.

In addition, particularly in Spain, the concept of cleansing of blood (purity of blood) which not only indicated a genealogy without ties to non-Christian groups or groups considered impure (such as the Moors or Jews during the Inquisition), but also an absence of connections with social classes considered inferior. In this way the alleged blue blood became a guarantee and synonymous with “purity” of blood, therefore a symbol of aristocratic status.

The theory of hemophilia, the “disease of kings”

Another theory, certainly more dramatic, traces this characteristic of the blood to a pathology, thehaemophilia, also known as “disease of kings”, a hereditary disease widespread among European nobility, further aggravated by frequent crossbreeding between relatives aimed at preserving their blood purity. Hemophilia causes a defect in blood coagulation, favoring hemorrhages, causing bruises And bluish swellings. In this hypothesis, blue refers to swelling.

Expansion of use

Although originally the use of the expression “blue blood” was closely linked to the European aristocracy, over time the term has taken on a broader and sometimes ironic. Today it can refer to anyone who behaves in an elitist or snobbish manner or who maintains an attitude detached from the daily problems of “common people”. This usage also reflects a change in social structures and in the perception of nobility, which is no longer necessarily seen as an ideal to be emulated, but rather is increasingly perceived as a legacy of a bygone era, associated with unjustified privileges and a disconnection from modern social reality.

noble wigs from the seventeenth century to the seventeenth century