When and where did the term 'knight' first originate?

The word knight derives from Old English (Anglo-Saxon) cniht, meaning page boy or servant, which in turn was likely derived from German Knecht, which also meant boy or servant. The first knights were cavaliers (men who fought on horseback) sworn (by an oath called fealty) to the personal service of their liege-lord or king. In European languages other than English, the words used for "knight" relate to riding horses. For instance, in most Germanic languages knights are called Ritter or ridder (literally "rider"), in French they are called chevalier and in Spanish caballero, both of which derive from vulgar Latin caballus, meaning horse. Chivalry, another French word related to cavaliers, was the code of honor for knights, and chivalry entered the English language through a popular medieval French story called The Song of Roland, which was a heroic tale about the knights who served under Charlemagne.