This term for nobility comes from the Spanish sangre azul
However, the most recent known origin, 
that... [DOC] [TLE] Nobility - Wikipedia [PAR] Nobility is a social class, normally ranked immediately under royalty, that 
possesses more acknowledged privileges or eminence than most other classes 
in a... [DOC] [TLE] Blue Bloods | Anomalies: the Strange & Unexplained [PAR] The actual origin of the term Blue Blood for royalty comes from the Spanish 
phrase Sangre Azul (literally blue blood), used to describe the fact that when 
the... [DOC] [TLE] blue blood | word histories [PAR] Jul 23, 2015 ...