What Ribe was, first, was a market. Danes, Norwegians, Swedes, Germans, Frisians and English all brought goods up the river from the North Sea to trade on the north bank - there was no natural harbour, just a flat sandy coast and a river a boat could enter. Ribe was minting money almost immediately. Of the three hundred-odd sceattas, the small silver pennies of the early medieval North Sea world, that have turned up in Denmark, 216 come from Ribe or its immediate surroundings, most of them of the Frisian Wodan type and most likely struck here in the early eighth century. Coins may have been produced as early as 720. Early in the ninth century the town enclosed itself with a two-metre ditch around twelve hectares - a boundary rather than a defence - and later replaced it with a moat six or seven metres wide. Archaeologists describe an active and impressive marketplace in the eighth and ninth centuries.

Then the evidence thins to almost nothing. Ribe is busy again by the end of the eleventh century, but for the intervening stretch the ground has little to say, and the town may have shrunk badly or emptied out altogether. Whatever happened, it recovered. A diocese was established here in 948; the cathedral school traces itself to at least 1145; the Treaty of Ribe was proclaimed in 1460. Riberhus, the royal castle probably built by Eric V in the 1200s, is now a moat and some grassy earthworks. In the end Ribe was undone by silt. The natural sedimentation of the Wadden Sea gradually closed the river to seagoing vessels, and Denmark's most important trading town became a provincial one. Nobody had reason to knock it down and build something bigger - which is why the medieval street plan survived intact. The town centre burned on 3 September 1580, and most of the houses standing there today date from the rebuilding that followed.

In 1637 a tailor named Didrik accused Maren Spliid of witchcraft. Her husband was a prosperous tailor too, and Didrik was not; that rivalry is the whole visible cause of what followed. He testified that three witches had come to him in the night, one of them Maren, and that she had blown into his mouth, after which he vomited something the clergy declared unnatural. Ribe acquitted her, with her husband standing by her. Didrik appealed over the town's head to King Christian IV, who ordered the case reopened in 1639 and demanded she produce fifteen character witnesses. When she could not, she was convicted. The king had her brought to Copenhagen and tortured - illegally, before any final judgement - until she confessed and named others. On 9 November 1641 she was tied to a ladder outside Ribe and the ladder was thrown into the fire. Her house still stands, and a plaque marks what was done to her; the HEX! Museum of Witch Hunt opened in the town in 2020.

Ribe sits low in a wide marsh, which has always been the cost of its position. Storm surges have come in repeatedly, and the worst arrived on the night of 11-12 October 1634, when the water rose more than six metres above normal and drowned people and livestock across the whole marsh coast. Marks on the cathedral walls record it, and a flood pillar in the town carries the levels of the great surges with 1634 at the very top - a monument you read by looking up further than seems reasonable. The Wadden Sea is a UNESCO World Heritage site now, tidal flats and salt marsh and enormous bird passage, and the Wadden Sea Centre a few kilometres out of town exists to explain it. Ribe VikingeCenter, two kilometres south at Lustrup, has built the eighth-century town back at full size.

Ribe has sent people out. Hans Tausen led the Danish Reformation from here. Hans Adolf Brorson, bishop from 1741, wrote hymns Danes are still singing. Rued Langgaard, a composer whose music the Copenhagen establishment refused, spent his last thirteen years playing the cathedral organ. But the one with the longest reach is Jacob Riis, born in Ribe in 1849, who emigrated to New York, took up a camera, and used it to force middle-class America to look at the tenements its poor were living in. How the Other Half Lives came out of that work. A boy from a town of a few thousand people grew up to document the most crowded slums on earth. Ribe itself waits. It calls itself the town of storks, and every spring the rooftop nests are cleaned and made ready, whether or not a pair decides that year to stay.