So here's what I was thinking, broadly:
It would be set in the CE period just after Islam has been established so we can include them as a religious group. It would be a story set after a fierce battle has raged and no-one quite knows what caused it and there are still warring factions, but lots of political intrigue, who really fought for who, religious, ethnic, political and other divisions (I think it would be cool to have Gnostics, Pagans, Sufis and other such groups included as well) and the point is to unravel the political intrigue about the various kingdoms, political ties, scandals, apostasies, secret marriages etc. Characters such as corrupt clergy, fake royalty etc. would be cool.
It would be PG-13 though so any sexual content between two people (secret affairs etc.) would have to be essentially euphemised ('he took her into his tent' and we'd get the implications) etc.