LONDON.- An extraordinary letter from William Blake to the painter Ozias Humphry describing in great and powerful detail his famous water-colour, The Last Judgement, is for sale as part of the Roy Davids Collection of Papers and Portraits at Bonhams on Tuesday 29 March 2011. Among the longest and most important of Blake’s known letters it is effectively a literary essay on his painting and is estimated at between £50,000 and £60,000.

Letters in Blake’s own hand are very scarce - only 90 are believed to exist. The originals of many are hard to trace and, of the known letters, most belong to institutions. In the past 35 years only two documents by Blake – a one page letter about his health and a receipt – have appeared at auction.

The Last Judgement was commissioned through Humphry for the Countess of Egremont to hang at Petworth House where it remains to this day. Blake’s letter explains the design of the picture in wonderfully stirring, almost Biblical, prose. Here he is outlining the left hand side of the painting, “appropriated to the Resurrection & Fall of the Wicked.”

“The Book of Death is opend on Clouds by two Angles: many groupes of Figures are falling from before the Throne & from the Sea of Fire which flows before the steps of the Throne....many Figures Chaind & bound together fall thro’ the air, & some are scourged by Spirits with flames of fire into the Abyss of Hell which opens to receive them beneath, on the left hand of the Harlots seat; where others are howling & descending into the flames & in the act of dragging each other into Hell & of contending in fighting with each other on the brink of Perdition.”

There is evidence that Blake originally intended the water colour as an extended sketch for a larger oil painting on the same theme. That work was never executed or if it was, has never been found. The Petworth House water-colour, therefore, is the nearest we have to Blake’s vision.

The importance to the artist of both the commission and the finished work itself can be seen by the fact that the letter from Blake to Humphry exists in three, slightly different, copies. All are in Blake’s own hand and internal evidence strongly suggests that this version of the letter was a fair copy of the first draft and was intended to accompany the painting to Petworth. Because of Humphry’s very poor eyesight it seems that the draft was sent instead where it was found at the back of a drawer at Petworth in 1952.

The sale of the Roy Davids Collection of Papers and Portraits is the finest of its kind in over 40 years. It will consist of over 500 lots of literature, history, travel and exploration, art, science, philosophy and psychology interspersed with portraits.