The Ghost of a Flea (c.1819) © Tate

As Blake turned sixty, his work at last began to find passionate admirers among younger artists, such as the watercolourists John Linnell and John Varley. It was Varley who encouraged Blake to draw sketches of his 'spiritual visitants', of which the most famous is The Ghost of a Flea. Linnell, meanwhile, despite being over thirty years Blake's junior, commissioned works for himself, and helped Blake secure commissions from others. It was thanks to his influence that Blake made the woodcuts for Robert Thornton's schooltext of Virgil's Pastorals in 1821. And Linnell himself ordered a duplicate set of the watercolours of The Book of Job (originally produced for Thomas Butts) and commissioned the series of drawings from Dante's Divine Comedy in 1824.

In 1821, Blake moved to a couple of rooms in Fountain Court, Strand, from which he could see the Thames. His young admirers called him 'The Interpreter', and confident in the judgement of posterity, he grew into a gentler and less angry man.

In the spring of 1827, Blake fell ill. A friend at his deathbed said he died 'singing of the things he saw in heaven' on August 12 at the age of sixty-nine. He was buried in an unmarked grave in the dissenters' graveyard at Bunhill Fields. One of his last acts had been to draw a picture of Catherine, his loyal wife and helpmate, from his deathbed.