All four Gospels place John at the Jordan, and the baptism of Jesus there, with the opened heaven, the descending dove and the voice, is among the few episodes all four report. From it Christian baptism took its form, and the eastern churches kept the river itself in the rite: at Theophany on 6 January Orthodox clergy bless water and in many places throw a cross into a river, lake or harbour for swimmers to retrieve, an annual re-enactment of what happened here.
The Mandaeans made the river a category. Their masbuta, the repeated immersion that is the centre of their religious life, requires living flowing water, and every such water is called a yardna, from the name of this river, wherever in the world the community now lives. Jorunn Jacobsen Buckley's work follows that community from southern Iraq and Iran into a diaspora now scattered across several continents, still needing running water to practise.
The modern river is a fraction of what it was. Israel, Jordan and Syria between them divert the great majority of its flow, the lower reaches carry agricultural runoff and treated effluent, and the Dead Sea it feeds is falling by about a metre a year. The traditional baptism site on the eastern bank at al-Maghtas and the western site at Qasr al-Yahud both sit in a former military zone; the minefields around the western churches were cleared only from 2018.