In "Roman Britain", room 49 of the British Museum, there is an enormous, highly decorated silver dish. In its centre is the face of the god Oceanus, his beard tangled with seaweed fronds. Around him dance sea nymphs and sea stags, while in the outer circle Bacchus, god of wine and giver of ecstasy, eats grapes and holds his staff, accompanied by hedonistic friends. The figures are so exquisitely depicted, they appear to dance off the dish.
It is an awesome artefact - as it would have to be to bring together two of the century's great free spirits: writer Roald Dahl and illustrator Ralph Steadman.
The Oceanus Dish is part of the Mildenhall Treasure, one of the finest collections of Roman silver found in Britain. It was unearthed by a Suffolk ploughman called Gordon Butcher in 1942. Dahl, who was then a little-known short-story writer, read about the treasure in a newspaper in 1946, after the discovery was finally reported to the authorities.
Responding to the "shivers of electricity" running down his legs, he dashed off to interview Butcher and another Suffolk man called Ford. Ford was the agricultural engineer to whom Butcher turned when he saw the first piece of silver glinting from the soil, and he cheated Butcher of a reward that might have reached £1m - a fabulous amount in the 40s. Ford declined to talk, but Dahl wrote the story anyway, splitting the profits with Butcher. That tale is now being republished as a book, accompanied by Steadman's illustrations.
Three years ago, when asked to do some pictures for a collection of Dahl's works, Ralph Steadman met the writer's widow and visited the hut where he had worked. Dahl had made a hole in the back of his writing chair to accommodate swellings on his spine from a wartime injury. He also kept bits of his spine and hip from the operations in little bottles on the desk. Through Steadman's pen, this chair metamorphosed into a dream machine. The hole was a magical hole you would go down to find stories.
When Jonathan Cape invited Steadman to illustrate more of Dahl's work, the only thing he wanted to draw was the Mildenhall Treasure - partly because he wanted to steer clear of stories that had already been handled by Dahl's regular illustrator, Quentin Blake. "It's about ordinary people and deceit and greed, and Dahl told it in a wonderful storyteller's way, even though it's a journalistic piece," he says. "Ironically," he adds, "Butcher and Ford are both lying practically side by side now in the same graveyard outside Mildenhall." He found this out while on a reconnaissance trip to Suffolk, where he was disappointed by the "boringly flat" landscape.
Steadman also visited the British Museum, where he was entranced by the detailed work on the plates. He was keen to get into the "fantasy" of the work and away from literal representation. In the same breath he says: "I hate the word illustration - it always sounds like a diagram," and, "It's absolute, downright, unforgiving laziness on my part that I prefer to draw in a free way, not slavishly copy things."
You feel this tension in the mix and construction of these wonderful pictures. A few are conventionally figurative. In others, he uses photocopies of farm machinery and bone (like Dahl's bits of hip), overlaying the photocopies and drawings with wildly energetic splatters and blotches of ink.
Steadman became obsessed by tractors, doing preliminary drawings in a farm museum. The blood-red plough blades (perhaps the colour was inspired by Butcher's name) dig like claws deep into the earth. The publishers thought there were too many tractors, but Steadman argued that the suspense of the story is created by a "tractor ballet", in which the machinery slowly dances closer to its "prey". "When I get on a tractor to cut the grass people tell me I always sing," Steadman muses, launching into his own tractor-inspired rendition of Ride of the Valkyries.
But it is the second half of the book, where Steadman allowed himself to get fully carried away by re-imagining the treasure, that really stands out. Beautiful blues and greens suggest not only the oxidised patina that had formed on the silver, but also Ford's jealousy and the freezing weather.
After the plates have been lifted from the earth, the silversmith's reliefs come to life, echoing and appearing to influence the human story. A golden Pan pipes in a golden den, pursued by a golden maenad. "I know the Roman silver is silver," says Steadman, "but gold is what you think of. They were unearthing an energy."
Skeletal characters enter into gladiatorial combat. The great dish turns like a Catherine wheel spilling figures including Fawcett, who is cradled by a naked woman. To get the density of a beaten-out relief, Steadman poured emulsion base on to the paper; this dries shiny and clear but also picks up the ink's colour.
"There is no anger in this story, but there is an ominous presence," Steadman concludes. "The treasure might have had a curse attached to it, and might still have one. In fact, people who buy the book might be cursed." This is pure Steadman "devilment". Roald Dahl would have approved.
The Mildenhall Treasure is published by Jonathan Cape, price £14.99.
