This word for a horsed warrior has an interesting history. It is Germanic in origin, but its cognates in Dutch and German, Knecht, mean farm hand, boy, slave, and servitude—a far cry from the English sense of nobility.
The earliest English sense of knight, or more accurately cniht, is also servant or boy. It is recorded in King Alfred’s Orosius, circa 893:
Philippus, þa he cniht wæs, wæs Thebanum to gisle geseald.
(Philip, when he was a knight, was bound as a hostage to Thebes.)
This sense fell out of use in the 13th century, probably to avoid confusion with the second, more modern sense.
The sense meaning nobility (corresponding to Dutch and German Ridder and Ritter, respectively) stems from the idea that the knight was a servant of the king. From the Old English Chronicle, written sometime before 1100:
Þænne wæron mid him ealle þa rice men...abbodas & eorlas, þegnas & cnihtas.
(Then he was aware of all the great men…abbots & earls, thanes and knights.)
Thus in English, the servant became ennobled, while he remained low in the other Germanic languages.
Cavalier which is the literal equivalent of the Dutch or German words, dates to the 15th century and was adopted from the Spanish—hence the Latin root. While the denotation is the same as knight, the connotation is different. Cavalier was never an official title and its association with the supporters of Charles I in the English Civil War gave rise to the idea that cavaliers were noble, but distracted and careless.
(Source: Oxford English Dictionary, 2nd Edition)
Copyright 1997-2015, by David Wilton