Unruly: The Ridiculous History of England's Kings and Queens

by David Mitchell

What caused the Arthur pearl was the persistent longing of humans, of almost all eras and cultures, to hark back to something better. It’s a far more enduring psychological habit than a belief in progress. People found it much easier to believe in a rose-tinted view of the past than a utopian future. They still do: hence ‘Take Back Control’ and ‘Make America Great Again’.

There’s now been so much talk about King Arthur over the centuries that many people feel, like they do with ghosts, that ‘there must be something in it’. There is: it just happens to be deep-seated psychological need rather than historical reality.