The Instructions is the title of a work by the Argentine magician Jacques Belasis , (1526-1604). It is of great significance in our narrative because it contains the crucial passage recounting how the Aureate magician Thomas Godbless once caused the natural components of England - her trees, rocks, weather and so forth - to gratify John Uskglass by a loving declaration of their fealty to him[1, 68].
As the two magicians prepare to make what they acknowledge to be a very rash attempt to summon the Raven King himself into their presence, they soften what they fear he may well perceive as disrespect by humbly repeating this spell; but, crucially, when doing so they exhort England to set herself at the feet not of "John Uskglass" or "the Raven King" but "the nameless slave" - a descriptor that Uskglass once used of his early self. And so it is that Jonathan Strange and Mr. Norrell accidentally cause all of England to mistake Stephen Black for the Raven King! This briefly bestows on Stephen - who is after all merely a butler and no adept of magic - such immense power he is able successfully to destroy a fairy prince so experienced and so powerful as the gentleman with the thistle-down hair.