Minds run free with the debris of giants

John Boardman's latest book is an account of how the Greeks created a visual dimension for their history by weaving stories around the remains of the past that surrounded them, combining half-remembered realities from the Bronze Age with borrowings from near eastern mythology, and bringing to life strange natural formations and fossils of long-extinct creatures.

Standing ruins and accidentally discovered tombs provided a backdrop for legendary exploits; Greek myths are mostly set in real places that were occupied in the historical period, lending a heroic aura to the landscape.

Boardman explains why Greece was fertile ground for these inventions to take root: the archaic Greeks were separated from their Bronze Age past by a dark age in which technology, writing and memory had been lost, leaving a virtually blank canvas for their imagination. All that remained of their ancestors were curious objects and massive ruins that seemed to be the work of giants. With no written records from the earlier era, they were free to create a tradition that could accommodate changing realities and needs. It was a continuous process: into the myths and legends that initially grew up around relics from the Bronze Age and even the geological past, the people of later eras wove artefacts of the early historical period, attributing primitive-looking sculptures to the legendary craftsman Daedalus, and unfamiliar weaponry to the heroes of the Trojan war.

This was no idle exercise: the past was, as always, closely entwined with the present. Originally these stories may have served to explain or justify, to bolster individual and collective status, or to back up claims to land or power. Even in the sophisticated 5th century BC, the bones of Theseus, conveniently discovered on Skyros and identified by their superhuman size, could provide a pretext for Athenian aggression. Centuries later, Roman tourists flocked to see the tusks of the Erymanthian Boar, the egg laid by Leda, and the burial place of Hercules' finger.

Modern travellers have not been immune to this: in the 19th century William Gell thought he had rediscovered the rocks smelling of human flesh that his predecessor Pausanias believed were left over from the clay used by Prometheus to fashion mankind; and the same tendency will be familiar to any more recent visitor to Greece who has been shown the stamping-ground of the Minotaur or the death mask of Agamemnon.

The heroes themselves were visualised as human in form, and were represented for the most part with contemporary dress and equipment, but they were pitted against terrible monsters, composite creatures that are among the most enduring images of Greek art. Here Boardman draws on Adrienne Mayor's recent work arguing that fossil bones gave rise to stories of monsters, giants and larger-than-life heroes, but he prefers to understand most of the creatures - griffins, sphinxes, sirens and the like - as purely artistic creations, forms borrowed from near eastern art and adapted to embody the horrors of Greek legend. The end products of these imaginings are familiar from classical and later art, but the fluidity of their appearance in early versions, and their cross-fertilisation with each other, are less expected. A particularly illuminating passage traces attempts to devise an image hideous enough to live up to the petrifying reputation of the Gorgon: one early painter imagined a woman in a thigh-flashing slit skirt, with a snake-rimmed cauldron for a head and a mouthful of fearsome teeth; later artists experimented with a centaur-like figure, a woman with a horse's hindquarters emerging from her skirt; finally, they settled on a leering half-animal face with lolling tongue, apparently borrowed from an Oriental demon (missing from this bevy of bizarre composites is yet another rejected version, with a winged human torso, feline forelegs and a sea-monster's fishy tail).

As well as artistic representations, Boardman draws on ancient literary references to relics of the past, and collects several hundred of them in an appendix. Unfortunately, these tantalising snippets are paraphrased, presumably for reasons of space, and thus do not convey the often-eccentric flavour of the original texts. Information on these texts is provided in the notes, so the interested reader can pursue them, but the lack of a separate bibliography is frustrating.

Boardman is the doyen of classical archaeology, and this book brings together for the general reader knowledge and insights accumulated over a lifetime's study of Greek art and iconography. It is beautifully illustrated, and is a fascinating compendium of intriguing information, ingenious conjectures and offbeat facts, mixing the familiar with the obscure - ample food for thought for anyone interested in mythology, folklore or their representation in the visual arts.

Ruth Westgate is lecturer in ancient history and archaeology, Cardiff University.