blue blood

B

blue blood (idiom)
/ˈbluː ˌblʌd/

The phrase “blue blood,” used to describe a person of noble or aristocratic descent, has a rich and debated history.

Meaning

• A member of a rich and upper-class family.
• Belongs to a family of noble or aristocratic heritage.
• Originates from a wealthy or high‑status family.
• Displays elitism or pride linked to noble ancestry.
• In zoology, refers to animals whose blood contains hemocyanin, giving it a blue appearance.

Synonyms: aristocrat; noble; patrician; highborn; elite.

Example Sentences

1. She comes from blue blood and grew up in a historic manor.
2. He may have blue blood, but he still works hard for a living.
3. His blue blood attitude made him seem distant from others.
4. The horseshoe crab is known for having blue blood.

Origin and History

The Spanish Nobility Theory

The most widely accepted theory traces the phrase back to medieval Spain. In its Spanish form, sangre azul (“blue blood”) was used by the aristocratic families of Castile. These families claimed their lineage was pure, free from intermarriage with Moors, Jews, and other groups who had lived on the Iberian Peninsula.

Because they spent little time outdoors, their skin remained pale. This made the veins under their skin appear more prominently blue, a visual sign they believed symbolized their “pure” heritage.

The nobility also did not work in the fields, avoiding the suntanned appearance of laborers. This visible contrast between pale‑skinned aristocrats and darker‑skinned workers became a symbol of high status and prestige.

The Role of Royalty and Inbreeding

Another perspective connects the term to the royal families of Europe. Over centuries, European royalty often practiced inbreeding to preserve dynastic power and wealth. This limited genetic pool sometimes led to hereditary conditions, including hemophilia.

Hemophilia, known historically as “the royal disease,” was common among European royal families such as those of Great Britain, Germany, and Russia. While the condition itself does not literally cause blue blood, its symptoms—such as easy bruising and subcutaneous bleeding—could give a purplish appearance under the skin. This connection may have helped reinforce the “blue blood” association with royalty and noble lineage.

The Symbolism of the Color Blue

In many cultures, blue has long been linked to nobility, divinity, and high social standing. In medieval and Renaissance Europe, blue was an expensive pigment to produce and was often reserved for religious art, royal clothing, and important ceremonial garments.

Because of its rarity and prestige, blue became a symbol of wealth, virtue, and elevated status. It is possible that the idiom “blue blood” also drew from this symbolic meaning, portraying nobility as set apart and “marked” by this exalted color.

The First Appearance in Print

The earliest known appearance of blue blood in English dates to 1834 in George Borrow’s The Bible in Spain. Borrow used it as a direct translation of the Spanish sangre azul, referring to Spanish aristocracy.

From there, the phrase quickly spread in English usage, eventually being applied to aristocrats of any nationality. Its literary introduction reinforced the Spanish origin theory and firmly established it as an idiom in English.

Final Thoughts

The origin of blue blood is a layered story with historical, cultural, and biological dimensions. The Spanish sangre azul explanation remains the most widely accepted, supported by both linguistic evidence and historical social customs.

However, other perspectives—such as associations with royal inbreeding, hereditary conditions, and the symbolic value of the color blue—add depth to the term’s cultural journey. Together, these influences have shaped a lasting idiom that still carries the weight of history in its meaning.

Variants

• blue-blooded.
• blue bloods.

Blood, Color, Rich, Wealth

Last update: August 3, 2025 8:45 AM