Artaxerxès (II Mnémon) roi, grand roi, ou roi des Perses dans le roman de Chariton Chairéas et Callirhoé. Quelle différence dans l’usage de ces titres ?

Xenophon seems to inspire the novelist Chariton, not only for the portrait of some characters of the novel, but too for some situations; furthermore, the novelist seems to borrow from the author of the Anabasis and the Hellenica the expression ‘King of the Persians’ to evoke him only in a context of wars, unlike the other Greek authors. The novelist uses the other imperial titles like ‘Great King’  in a political context, and ‘King of the Kings’, in a kind of official correspondence, unlike the other Greek authors. Using the three titles, Chariton seems to remember all the Iranian imperial titles, from Darius the first till Darius the second.