Now she is a parcel of bones and shrivelled flesh to which is attached a redeeming bust-length portrait of her as she was in life. Painted by a gifted but anonymous artist one day nearly 2,000 years ago, then bound across the face of her mummified corpse by a meticulous Egyptian embalmer, the picture shows us that Hermione once had sad, liquid eyes and full lips. Her dark hair was centre-parted and combed back tightly behind her ears. She had high cheekbones. She wore pearl earrings and a plain pale tunic.
Listed as catalogue number 11 in the British Museum's current exhibition, "Ancient Faces: Mummy Portraits from Roman Egypt", the Portrait of a young woman, inscribed in Greek 'Hermione grammatike' in encaustic on a linen shroud within a complete mummy was donated to Girton College, Cambridge, in the early years of this century by the archaeologist Sir William Flinders Petrie. Imagining Hermione to have been a rather prim and schoolmarmish young gel (undoubtedly Oxbridge material), he thought she would feel at home there. The bequest was his almost fatherly way of acknowledging the power of an image. Flinders Petrie had dug her from the ground but, when he looked at Hermione's portrait, he could not help thinking of her as alive. Looking at her now, it is hard to blame him.
The so-called Fayum portraits, named after the part of Egypt in which the first of them were originally unearthed, are among the most haunting pictures of human beings in existence. They were produced by a confluence of ancient civilisations in the Eastern part of the Roman Empire. In Fayum and other settlements along the Nile, Egyptian society absorbed several waves of Greek immigrants after the conquests of Alexander the Great. The Greeks who eventually settled in Egypt - mercenaries, most of them, who rented out their services to the Ptolemaic kings - gave up their own gods and embraced those of Egypt. But they preserved other elements of their cultural inheritance intact. During the period of Roman rule, Pharaonic Egyptian burial practices - which Romans found odd but were prepared to tolerate - were gradually modified to accommodate Hellenistic traditions of painting.
So it was that the ancient Egyptian mummy, that brittle and forbiddingly idealised monument to a civilisation's overwhelming fear of death, became a yet frailer but more humane form of memorial. The cartonnage masks of ancient precedent were replaced by portraits, painted in hot or cold wax on to strips of linen, from which the Greco-Egyptian peoples of the first three centuries AD still stare out at us with such disquieting self-possession.
To come face to face with a whole society, as we do before the portraits of the men and women of Roman Egypt, is to be forcefully reminded of how very little people have changed during the past two millennia. We look into their eyes and we know that they walked and talked and ate and breathed and fussed and worried as we do. That large and rather daunting word, "Antiquity", is an inadequate abstraction. The past is not as foreign a country as we often imagine it to be.
The 19th-century discovery of the Fayum portraits was equivalent, in the field of art history, to the finding of a Missing Link. With the exception of a few murals, notably in Pompeii, these works are the only surviving examples of that fabled Greco-Roman tradition of painting said to have been founded by Apelles, court painter to Alexander the Great, in the fourth century BC. In his Natural History, Pliny the Elder maintained that Apelles had been the greatest of all painters to have lived; and the first-century comic author Petronius, who claimed to have seen some of his works in a private art gallery in Rome, declared that "the outlines of the figures gave a rendering of natural appearances with such subtlety that you might even believe their souls had been painted". But, until Flinders Petrie made his find at Hawara in 1888, it was impossible to know how much hyperbole was mixed up with Latin authors' proclamations of the Greek genius for painting.
Thanks to the singular burial practices of the Egyptians, the Greek settlement of the Nile and the preservative climate of the North African desert, we can form at least a tenuous notion of Apelles' skills from the works of the Fayum portraitists. Some are extremely crude. Later examples begin to show a stiffening of the human face once more into an inscrutable icon. But the most accomplished of them are astonishingly sophisticated in their illusionism. Petronius, it seems, did not exaggerate. The sense of human presence conjured by the portraits is indeed stunning.
The range of techniques known to the Greco-Egyptian painters hints at the tremendous complexity of the lost traditions of art which their works embody. Some of the portraits were carried out in hot wax, a medium which required great speed of the artist and which produced, in the finished works, a powerful impression of the malleability of flesh and the fleeting nature of human expression. Others were carried out, more deliberately, in cold or "punic" wax, a medium close to egg tempera which tended to produce more idealised and statuesque likenesses. Not for some 14 centuries would Western painters, in the age of Masaccio and Van Eyck, start to recover the knowledge of how effectively, and how variously, paint can be made to stand in for living, breathing individuals.
Altogether around 1,000 "Fayum" portraits have been excavated, many of them not from Fayum at all but from a range of sites stretching from the Nile Delta more than 300 miles up river to Panopolis. Some 200 have been assembled at the British Museum. Most have long been detached from the mummies to which they were once fixed, which seems a particularly brutal severance of art from its original context. Despite that, they cannot easily be mistaken for more trivial or light-hearted forms of portraiture. These faces are too severe for that - too earnest, too naked and too alone before whatever vastness it was that they believed themselves about to confront.
In the introduction to her book The Mysterious Fayum Portraits, the painter and scholar Euphrosyne Doxiadis recalls the experience of being locked into a storage room in a museum in Berlin with a couple of dozen of these intense faces for company: "I felt a very strange sensation - that I was not alone. None of these portraits was still on its mummy, and yet they transmitted the energy of human beings." Seen in daylight, in the company of others, they are no less spooky. These people did not want to die and these images are the spells which they wove against their own extinction.
They seem to watch you with an air of melancholy and not a little resentment, this misanthropic tribe of the dead trapped behind glass. The galleries of the museum are corridors filled with ghosts. You brush past them, but not easily. There's the handsome young man with his hair cut in the fashionable Trajanic fashion; the long-faced woman with her gold ball earrings, a single wet highlight of white paint suspended in each; the young athlete, with his head of tight black curls, down on his upper lip; the swarthy priest of Serapis with the entrancing eyes and the seven-pointed star of gold in his hair ...
Each one detains you, as if willing you to imagine him or her back into life. It is a form of immortality, perhaps. But you know it is not quite what they originally had in mindn
'Ancient Faces: Mummy Portraits from Roman Egypt' is at the British Museum, London WC1 (0171-636 1555). To 20 July