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

“Pseudo-Dionysus ranks the Thrones amongst the highest third of his nine (three by three ranking) orders of Celestial Beings and gives to them the function of showing forth the Divine Radiance.

‘The name of the most glorious and exalted Thrones denotes that which is exempt from and unattained by any base and earthly thing, and the super mundane ascent up the steep. For these have no part in that which is lowest, but dwell in fullest power, immovably and perfectly established in the Most High, and receive the Divine Immanence above al passion and matter, and manifest God, being attentively open to divine participations.’

Chapter VII: Of the Seraphim, Cherubim & Thrones & their first Hierarchy” [via]