Richard Dadd murdered his father in a psychotic episode and spent the rest of his life locked up in Bedlam and Broadmoor. In spite of the (slightly Blakean?) picture here of a madman in chains, Bedlam had become a more enlightened place by then, and Dadd, already an established artist, was able to continue painting, sometimes doing portraits or commissions for the staff. One of these was to prove by far his most celebrated work, namely The Fairy Feller’s Master-Stroke. Although some of his other paintings are a little strange, this one is in a league of its own, and I don’t think the poem Dadd wrote about it helps explain all that much. He considered the painting unfinished, and you can see that an area at the bottom left is only sketched in.

The current exhibition at the Royal Academy shows that Dadd was a real master in terms of technical skill. I don’t think I have ever seen watercolours so crisp, precise and confident. He was known for painting fairies and he liked a bit of Shakespeare, but generally his realism is impeccable and the weird distortions in Fairy Feller are only echoed in one or two other works. Most of them are interesting but Fairy Feller is the one you could spend all day looking at.