The written record begins in 913, though archaeologists have found people living here well before that. What made the place was the Landgraviate of Hesse, which used Kassel first as a centre and then as its residence, and a princely seat generates the things princes want: a court, a theatre, collections, gardens, and eventually a hillside park that would take a century and a half to finish. Hesse-Kassel also came down firmly on the Protestant side, which mattered enormously later, because when Louis XIV revoked the toleration of France's Protestants, thousands of Huguenots went looking for a landgrave who would have them. They arrived with trades, skills and capital, and they stayed. Walk the centre now and you find their surnames on the street signs - one of the few things in the middle of Kassel that survived 1943 intact, because names are not flammable.

Among those Protestant exiles was Denis Papin, a French physician and inventor who ended up in Hessian service and who built, in Kassel, a pressure vessel that could throw a jet of water into the air using nothing but heat. He was working on the steam engine roughly a century before the steam engine happened. The local telling goes further: that Papin put an engine in a boat and left Kassel under steam power years before James Watt had a working prototype, which is a claim historians treat with more caution than Kassel does. Either way, the machinery survives in spirit at the Orangerie in the Karlsaue park, where a superb collection of Enlightenment instruments - clocks, globes, astronomical devices, calculating machines - shows what a small German court could buy and build when it decided that natural philosophy was worth money.

By the twentieth century Kassel was making locomotives. Then, under the Nazi regime, it was making tanks and aircraft as well, and that is the whole explanation for what happened in October 1943. The bombing was not incidental to the city's character; it was a consequence of it. Kassel was hit repeatedly through the war by British and American aircraft, but the October raid was the one that broke it. Something worth holding onto: the ten thousand who died were overwhelmingly not the men who ran the factories. They were families sheltering in cellars beneath centuries-old half-timbered houses, in streets too narrow to escape down once the fire took hold and began pulling air in behind it.

West Germany reconstructed Kassel at speed and on a budget, and the result is one of the more honest ugly city centres in Europe - honest because nobody in Kassel pretends otherwise, and contemporaries said so at the time. There was no money for reconstruction in the old manner and, in the 1950s, not much appetite for it either. What went up instead was plain, functional and cheap, and the inner city today is largely banks, offices and shopping galleries. The consolation is that the city works. Kassel is a major node on the German high-speed network, sitting on the first purpose-built ICE line between Würzburg and Hanover; Kassel-Wilhelmshöhe station handles the fast trains four kilometres west of downtown, while the handsome old Hauptbahnhof has been repurposed as the Kulturbahnhof, a station given over to culture because the trains no longer need all of it. Every five years documenta arrives and fills the whole place with contemporary art, and on the first Saturday of September the museums stay open past midnight for Museums Night - sixty-one venues took part in 2025, on one ticket.

Jacob and Wilhelm Grimm lived and worked in Kassel, and it was here that they assembled the collection published in December 1812 as Kinder- und Hausmärchen: Hansel and Gretel, Rapunzel, Snow White, Sleeping Beauty. The fairy tales made them famous. Their real life's work did not. The Deutsches Wörterbuch was to be a complete dictionary of the German language, every word traced to its root, and the brothers had no realistic idea what they were starting. The first volume appeared in 1854. Jacob died in 1863 with the work stalled somewhere in the letter F, and it was finished - by other hands, generations of them - in 1961. The city keeps a museum devoted to the brothers, and the countryside around still trades on them: the German Fairytale Road runs through, the Reinhardswald north of the city holds the castle of Sababurg that people insist is Sleeping Beauty's, and the Habichtswald forest presses right up against the western edge of town. Two brothers spent their lives insisting these stories came from ordinary German people. The landscape has been happily agreeing with them ever since.