Tigris River

The Tigris is the eastern of the two Mesopotamian rivers, faster and less predictable than the Euphrates, and the great Assyrian cities stood on it: Ashur, Nimrud, Nineveh, and later the Parthian and Sasanian capital at Ctesiphon.

Genesis names it as one of the four rivers flowing out of Eden, alongside the Euphrates and two others whose identification is disputed, which places the biblical paradise in the Mesopotamian imagination rather than an unlocated one. That association was taken seriously for a very long time: medieval maps put Eden at the head of these rivers, and travellers looked for it there.

The river carried the cult as well as the cities. Assyrian royal inscriptions describe kings crossing it on campaign and setting up images at its source; the practice of throwing offerings into water is attested across Mesopotamia; and the flooding of both rivers underlies the flood narratives that the region produced in several languages.

Later it was a boundary between empires. Rome and Parthia, then Rome and Persia, fought repeatedly for control of the country between the rivers, and the Christian churches that grew up on the Persian side developed in Syriac and outside imperial Roman jurisdiction, which is why the Church of the East is doctrinally distinct from both Byzantium and Rome. Baghdad, founded on the Tigris in 762, became the centre of the Islamic world for five centuries.

The Mandaeans are the last surviving Gnostic community with an unbroken tradition, and their religion is bound to this river system in a way few others are bound to any geography.

Their central rite is immersion in flowing water, performed frequently rather than once, by a priest, in a river, with a specific liturgy; their word for such water is yardna, the same root as Jordan, applied to any living stream. They honour John the Baptist as a great teacher, reject Jesus as a false messiah, use a distinct script and an Aramaic dialect of their own, and possess a substantial body of scripture including the Ginza Rabba. Priesthood is hereditary and the ritual requirements are demanding, which makes the loss of priests a direct threat to the religion's continuation.

The community lived along the lower Tigris and Euphrates and in the marshes between them, in Iraq and southwestern Iran, for at least a millennium and a half. Jorunn Buckley's work with the community and its manuscripts documents both the tradition and its scribal transmission, which she has been able to trace through colophons back many generations.

Since 2003 the Iraqi Mandaean population has collapsed, from tens of thousands to a small remnant, through targeted violence and emigration. Most Mandaeans now live in Australia, Sweden, the United States and elsewhere, in places with no river a priest can use, and how the rite is to be maintained is an open and pressing question for the community.