The term “blue blood” refers to someone of noble birth or aristocratic lineage and has a well-documented origin. Although commonly associated with British royalty, it first emerged in medieval Spain, where it was used to describe the pure-blooded nobility, especially those of Visigothic ancestry, descended from the Visigoths – a Germanic tribe that ruled parts of Spain after the fall of the Roman Empire. These nobles were keen to distinguish themselves from those with Moorish or Jewish heritage.
Unlike the working class, aristocrats lived lives sheltered from outdoor labor and sun exposure, which gave them noticeably paler skin. This made the bluish veins beneath their skin more visible, especially on the forearms. In contrast, peasants and laborers had darker skin that concealed their veins. The visibility of veins became a symbol of high status, and the phrase sangre azul, or “blue blood,” came to define noble lineage. The term later spread to other parts of Europe, including Britain, where it is still used figuratively.
