An Historical Summary of Angelic Hierarchies from Part VII: The “Seven” Thrones in In Operibus Sigillo Dei Aemeth by David Richard Jones.

“It is important to understand that there was, for Dee and Kelly, a standard Renaissance view of the divine order and the place of the various echelons of angels within that hierarchy. This view was defined primarily from scripture, but drew the precise form that it did from the Celestial Hierarchy of St. Denis, the Aereopagite, so-called.” [via]