King and obedient spirits

Meaning

The king here is the hidden spirit praised in the philosophers’ reported encomium. Other heavenly spirits obey it because it is described as exceptionally subtle, noble and pure. Royal authority expresses a hierarchy of powers and the breadth of the benefits claimed for the art.

The English ‘as to their king’ keeps the comparison visible. The passage does not identify a political monarch or independently demonstrate command over actual spirits. Nor should this localized royal metaphor be silently exchanged with every ‘heavenly king’ in the later Christological allegory, where the named agent and theological claim are different.