Who is Jaron from Persian Letters. Translated with an Introd. and Notes, by C. J. Betts and what is their importance?

Jaron is the black eunuch who traveled with Usbek and his group to Europe. Jaron trained under the head eunuch and although he would prefer to stay with Usbek in Europe, he is prepared to do the job he has been trained to do when Usbek decides to send him back to the seraglio.