While he was a teenager, William Collins wrote a set of this type of eclogu
While he was a teenager, William Collins wrote a set of this type of eclogues.  A play about the people of this name originally followed Phineas and preceded Glaucus Potneius in a trilogy of which it alone survives.  As an adjective, this word appears in the title of an epistolary work in which two noblemen named Usbek and Rica describe French society.  A 1972 novel by Mary Renault centers on a "boy" of this ethnicity named Bagoas, who becomes the lover of Alexander the Great.  FTP, give this word which describes the "letters" in a book by Montesquieu and which, when plural, names the oldest surviving play by Aeschylus.
While he was a teenager, William Collins wrote a set of this type of eclogues.  
Persian (accept The Persians or Persian Letters or even The Persian Boy)