A rare trial proof copy of Andy Warhol's 1985 portrait of The Queen is to be auctioned at Bonhams Print Sale in London on July 11. It is estimated at £40,000-60,000 (US$ 62,000-93,000).

The signed and numbered print, Queen Elizabeth II, is from the Reigning Queens series which also includes the Queens of Denmark, the Netherlands and Swaziland. It was his last print-portrait before his untimely death in 1987.

It is based on a portrait of Queen Elizabeth painted in 1977 to mark her Silver Jubilee. Given Warhol's fascination with transvestites of whom he painted a series in the 1970s called Drag Queens or Ladies and Gentleman, the Reigning Queens title is clearly intended as a pun on Raging Queens. The two series also share the same bright, almost garish palettes. As always with Warhol, however, the flippancy masks a more serious point about the nature of celebrity and image in the modern world.

Writing of Warhol and his portrait of the Queen in the latest edition of Bonhams Magazine, the artist, art critic and journalist Adrian Dannatt says, "Warhol was, of course, a commercial artist working in design, fashion and advertising for many years before he crossed over into the world of fine art. It is in his portraits above all that Warhol combined these two aesthetic domains, deploying all his graphic skill, his eye for engaging line and colour, his 'creative director' talents to make images that would not only appeal to his immediate clients, but also to absolute strangers in the years to come."