Ever since the Rostovtzeff's famous book Palmyra is commonly called a “caravan city”. As a matter of fact, it is the only real caravan city among those considered as such by the great scholar. Both Gerasa and Dura-Europos were calm, provincial towns living off the countryside, and no signs of a commercial vocation are on record in either. Petra was above all a royal capital, and the importance of its trade, though likely there, remains entirely to be demonstrated. We might now add that Hatra, also a royal city and a major religious centre, owed its prosperity more to these characteristics than to far-flung commerce.

I shall leave aside the Jordanian cities, Petra and Gerasa, very different from each other and from the other three, including Palmyra, which have participated in a particular brand of civilisation, often and rather mistakingly called Parthian.

These urban societies shared a common language, Aramaean, and a body of customs—religious and social—resulting from a mixed heritage in which a substantial nomad Arab contribution predominated over more ancient traditions of Syria and Mesopotamia. While practically no trace of Iranian influence can be detected, there was certainly a more or less thin veneer of Hellenism, generally supposed to have spread within the limits of the Parthian empire. Actually, there is not much to show in this respect for the Iranian part of the realm, or for the capital Ctesiphon. What is known concerns mostly the Greek cities of Susa and Seleucia, and does not manifest any close relation to the conditions of the Aramaic speaking cities we know further west. Whether Palmyra was a “spiritual daughter” of Seleucia, to quote an influencial and imaginative formula of Henri Seyrig's, is a question still waiting, after sixty years, for a documented answer.