Unknown

Sometimes I dream about textiles. A quiver of moonlit banners drift colour streams across a mirrored lake. Yards of soft-sheened silk are flung by villagers edging a river bank, cast into the water's flow, the people watching silently as the cloth, ripple-etched, is carried out to sea.

Most of my dream settings, however, are more prosaic; a deserted warehouse, a musty charity shop in which rails of clothes stand abandoned. I trail my hand through long-forgotten fabrics – crêpe de chine, duchess satin, tulle net – grazing my knuckles on a crust of beading, smoothing down languid lengths of fringing, stroking the braille of lace, drumming my fingers along a rhythm of pleats: small collapses of spent glory, discarded, uncherished, their makers unknown.

When I wake, it is always with a sharp pang of loss, more acute than might be felt for actual textiles. Because the textiles I touch in my dreams have never existed. There is no hope of their re-discovery.

I am on a train out of Paris, the hem of the city unfolding into a pretty patchwork of rural France. I'm on my way to Bayeux, where its celebrated tapestry is on permanent display. The tapestry is a rare survivor of medieval stitchery, now championed as a precious cultural relic deemed worthy of special safeguarding by UNESCO's Memory of the World Register. But it wasn't always so well protected. Indeed, for its first 500 years it languished in obscurity, its exposure limited to an annual outing as ecclesiastical decoration for the Bayeux Feast of Relics, when, for a few days, it would be looped around the nave of the cathedral as a reminder to the congregation of the triumph of right over wrong, of a French victory over the English.

The Bayeux Tapestry tells the story of the Battle of Hastings in 1066. It is an embroidered narrative cloth with fifty-eight numbered scenes depicted in linen cloth and wool yarn, the simplest of materials. At its heart, it is a morality tale: a warning of the cost of betrayal. It tells how the English Harold recanted his oath of allegiance to the French William and seized the throne of England for himself; how William retaliated, prepared for war, defeated Harold's army and conquered England. A wrong righted, arrogance and greed avenged.

Images of the Bayeux Tapestry are embedded in our popular culture. It has become an iconic illustration of medieval life in Britain, its stitched narrative reproduced in countless books, on greetings cards and as needlework kits. It is much beloved by cartoonists amused by the incongruity of medieval stitchers and sharp contemporary comment. All of this has won it familiarity, an affection of sorts. But although I have read about it extensively and seen numerous printed versions of it, I only know the tapestry one frame at a time. I have no sense of what impact it will have when I see it in its entirety, no real understanding of its scale or its tangible presence.

When I arrive at Bayeux station, the Musée de la Tapisserie de Bayeux seems disappointingly close. There is only a road to cross, a few hundred yards to walk, a conker-crunching stroll through a tree-lined carpark to reach the museum's entrance. I had hoped for more of a pilgrimage, a little more time to savour the quest.

I buy my ticket and snake through a surprisingly lengthy maze of red-corded barricades used to corral the swell of visitors in high season. The Bayeux Tapestry is a popular tourist destination, attracting close to 400,000 visitors a year. Even today, on a cold October morning, there is a queue. The girl at the desk hands me an audio guide and instructs me about its function keys, but in truth, I'm not listening. I am like a greyhound waiting for the retort of a starting pistol. I am ready for the off.

A long, dark room is illuminated by a gleam of cream, a river of textile that stretches as far as the eye can see and flows back on itself again. I forgo the audio guide; this is to be an encounter between me and the tapestry. I want it to be my guide, to hold me back or beckon me forward, to insist on discovery at its own pace.

The thrum of audio commentaries intrudes, and while I can block out its babel of different languages, I can't avoid the sonorous soundtracks, the chanting of medieval songsters whose voices follow me – rising and falling, rising and falling – to chorus my meanderings. For the Bayeux Tapestry invites promenading. I stroll along its banks, surprised at how easily, given its vastness, it draws you in to its smallest details: the pattern on a cushion, the emblem on a shield, the liquid spill from a pitcher.

It begins grandly with an ornamented, turreted palace with lions growling below on the border: a symbolic portent of warring kings. Edward, his name writ large above his sewn portrait (the soon-to-be-dead King of England), is counselling his son Harold about his mission of peace with France. Seventy metres later, it ends tragically: the border is strewn with the war-dead and there is a final distressing image of a naked and cowering English soldier clutching the torn-off branch of a tree as his only defence.

Unfolding between these two scenes are tales of feasting and farming folk, of spies and ship building, of hunting and harvests, of nobility on horseback and slain unarmoured archers, and of slaughter in the rough fray of battle. Its narrow frieze, only fifty centimetres high, has stylised sentinel trees to separate scenes. Embroidered borders provide an emotive and satirical commentary that amplifies meaning and mood in a procession of symbolic motifs and cameos of everyday life. Text travels across its surface in bold stitching to chronicle characters and events, and the visual story is punctuated by boasts of learning and travel: borrowings from Nordic sagas, images copied from illuminated manuscripts, designs culled from Greek and Roman sculpture and illustrations of some of Aesop's fables, including 'The Fox and the Crow' and 'The Wolf and the Lamb'. This is not just one story. This is a complex, multi-layered series of historical, biblical, mythical and cultural narratives, some of which we can still decipher, but much of which is long lost. We can no longer interpret all the tapestry's double meanings, unravel its intellectual challenges or unpick all the creative connections caught within its coloured threads.

It is generally agreed that the tapestry was designed by a man. The vivid illustrations of war preparations, the knowledgeable portrayal of horses and the detailed attention to weaponry all point to a male provenance. Recent research by the historian Howard B. Clarke of the University College in Dublin strengthens the case. He identifies Abbot Scolland, who died c.1087, the head of the illuminated manuscript scriptorium at St Augustine Monastery, as its likely designer because many of the tapestry's images seem drawn from life or memory and are...