Bit of a problem here. I haven't heard of a Greek translation of the name of the well-known series, probably because Greek equivalents do not automatically come to mind, nor do they sound equally appealing. So, what are we talking about here? Is this going to be another title in the series? Or the title of an independent work? Probably just the title of a web page.
If a Greek publisher were to come out with Greek translations of the Rough Guide series, I suppose he would keep the English name of the series or go for something different but equally appealing in Greek. If you do insist on a Greek translation for the complete title here, we would probably have to suggest something that is not exactly the same and let you choose on the basis of back translations.
For the time being, my only contribution is my suggestion to go for something like "υπό Έντουαρντ" for "by Edward" (even "υπό Εδουάρδου"). Sounds a bit more formal and goes well with the "Ancient Greece" part of the title.