The city they found, Dura-Europos, told Rostovtzeff what he already knew about the ancient world: It was a place of unbelievable cosmopolitanism and radical diversity. A Jewish synagogue, one of the earliest known, displayed Abraham and Isaac, as well as Moses fleeing Egypt. A Christian church contained the earliest painting of Jesus we have. The walls were inscribed with more ancient languages than many have ever heard of. Rostovtzeff, now well over 60, disturbed his colleagues by staring at the blinding white walls for hours, reading one item after another and placing each into his cosmic historical framework. In New Haven, the students and faculty of the Classics Department summoned their common expertise and published study after study, year after year, exposing for the first time material that had been hidden from the world since the third century A.D. (What is not in a museum is now gone again: Last year, ISIS raided the ancient city and demolished whatever they saw.)The context of the essay is the recent controversy over Yale's use of endowment funds of the Classics Department, on which see Classics dept decries admin “raid” on funds (VICTOR WANG, Yale Daily News).
There are many, many past PaleoJudaica posts on Dura-Europos. Start here and follow the links. The posts here and here seems particularly relevant to the article above.