The crypt is the site of the original shrine to Thomas Becket, the archbishop murdered by Henry II's henchmen in 1170 and later described by Chaucer as that "hooly blisful martir". Since the saint's death, pilgrims have flocked to Canterbury to view his bones, his clothes, even a sacred towel that once, in the words of the Renaissance scholar Erasmus, wiped "the perspiration from his face or neck, the runnings from his nose or any other superfluities from which the human frame is not free".
Most relics were destroyed during the Reformation, but a few remain today. These were the sights no medieval tourist would miss. Surrounded by holy body parts, candles, scraps of clothing, they would offer their prayers and material offerings - hoping, in return, for spiritual succour and healing.
Often, as recorded in Chaucer's Canterbury Tales, they had undertaken the journey on foot from London. April was the month when, traditionally, the roads were packed with pilgrims, breaking their journey to venerate every church, relic, resting place or holy well along the way. The trail began in London and can still followed to this day, taking in many of the same sites.
In Chaucer's time the faithful assembled at the Tabard Inn in Southwark, south of London Bridge. Today, they must cross the river and head north to St Etheldreda's Church in Ely Place, a private no-through street by the busy junction of Holborn Circus.
Most of the buildings along the short street are tall, Georgian town houses, but sandwiched between the elegant faades is the great west window of St Etheldreda's Church - all that remains of the medieval palace of the bishops of Ely, founded in 1293. The church, which survived the Reformation and was sold back to the Catholics in 1874, houses its own relic; requests to view it are met with good-natured mirth in the presbytery office.
"I think you have to have a touch of humour about these things," explains Father Kit Cunningham, as he produces a heavy gold cross from behind a door in the cavernous crypt. At the cross's centre, barely visible in the darkness, is a small white speck - a fragment of St Etheldreda's hand from her long-lost shrine at Ely. But for Father Cunningham, the devotion paid to such tiny relics is no laughing matter. "The piety of faith, the spirituality of everyday belief, should never be despised," he says.
Where St Etheldreda's is grey and overshadowed, the church of St James Garlickhythe stands alone by Upper Thames Street, its sandstone gleaming as new. With its many windows and its glass chandelier, the church, rebuilt by Wren after the Great Fire of London in 1672, is a monument to space and light. Upstairs in the tower, however, a small dusty room houses a darker treasure.
"You can still just about see that it's a man," comments Eileen Matthew, one of the church ladies, as she lifts the lid of a large wooden box to reveal "Jimmy Garlick" - the mummified corpse found under the chancel floor during the last century. You can also see every slender rib, each curled toe, and a perfect set of white teeth. Recent research suggests that these are the remains of Seagrave Chamberlain, who died at the age of 16 in 1675, and is commemorated on a church tablet. "As I am now," reads the inscription on his case, "so shall you be."
Chaucer's pilgrims left the city by way of Watling Street, now the A2, which still follows the course of the old road through the heart of the Medway towns. Modern pilgrims searching for tranquillity should head instead for the so-called "Pilgrim's Way", centuries older than Christ, which once brought medieval penitents across the North Downs to Canterbury from the west.
At Otford in Kent, where the archbishops of Canterbury once rested on their way to and from London, family-owned shops and half-tiled pubs still line the main street. But the archbishop's palace is now in ruins and the village is hemmed in by three teeming motorways. At Castle House, Andrew McDowall, who has lived there for 60 years, is trying to reverse the decline. "Ten years ago you wouldn't have been able to see it for the brambles," he says, showing me the remarkable stone well in his grounds. At 30ft long, 15ft wide and 8ft deep, it is now thought to be the remains of a Roman bath. To medieval pilgrims, however, this was Becket's well - springing up where the saint once struck his staff and endowed with miraculous healing powers.
Refreshed, or not, by the waters of Becket's well, climb the hill out of Otford, turn right towards Kemsing and you're on the Pilgrim's Way. The lane twists along the side of the North Downs, through high hedges strewn with wild flowers and out again across bone-white open fields. Despite the hum of the M20 far below, it's a landscape earlier wayfarers would have recognised: brick-and-tile farmhouses, church towers, neolithic tombs.
Leybourne Church, a few miles south of the Pilgrim's Way, has Saxon foundations, although stranded today by a busy main road. Even the relentless pounding of container lorries can't disturb the calm of its simple, whitewashed interior. Hidden in an arched opening in the north wall, there are two small stone caskets: the shrine of Roger de Leybourne, who died in 1271 on his way to the Crusades. The left-hand casket, explains Jack Jessup, the church's amateur archivist, contains Leybourne's heart, returned after his death to his boyhood home; the other, meant for the heart of his widow (who later remarried), is empty.
To 83-year-old Mr Jessup, who first sang in the church choir when he was eight: "It's my spiritual home; that's why I know it so well." Outside he points to a vent in the wall by the porch, used by wild bees as a hive since he was a boy - a relic of his own childhood, as precious as any sacred shrine.
Further east, at Aylesford, pilgrims crossed the Medway river. A few miles upstream is The Friars, originally founded in 1292 by the Carmelites, who returned in 1949 after an absence of 400 years. A new open-air church has now been built over the ruins of the old, but in a covered chapel by the high altar a reminder of the priory's medieval past lies at rest: the skull of St Simon Stock. "Non-Catholics can sometimes get upset about these things," says Brother Laurence, uncovering what appears to be a lump of polished clay. Yet it is apparently responsible for crowded annual pilgrimages and, Brother Laurence believes, many cures.
"You're not just talking about dropping crutches," Father Wilfred McGreal, the sub-prior, explains, "but a way of getting things together, a sense of peace."
East of Maidstone that sense of peace intensifies. As the peaks of the Downs flatten out, bungalow dormitories and industrial units become more common, but so do the more traditional sights of Kent: oast houses, hop- poles and flowering orchards. In Lenham church, the medieval altar stone still survives, hidden in the church floor from the purges of both Thomas and Oliver Cromwell. At Charing, however, the church's most famous trophy - the very block on which John the Baptist was supposedly beheaded - hasn't been seen since the Reformation.
Past Charing, the Pilgrim's Way veers north towards Canterbury along the top of the Stour valley. From here, tangled lanes lead down towards the remote church of Boughton Aluph, where pilgrims once sheltered by a fireplace in the south porch. The church is famous for another fire, started by an incendiary bomb during the Second World War and extinguished by the Wye Fire Brigade. "Pilgrim," reads an inscription on the north wall, "give thanks that this church survived the holocaust of war."
Just outside Canterbury, at Harbledown, medieval pilgrims paused at the 11th-century lazar-house of St Nicholas before entering the city. Today, its Norman chapel still perches on a grassy hill - Chaucer's "Bobbe-up- and-doun". Though the leper hospital has now been replaced by almshouses, some relics still survive. "There is a rusty old buckle in the church," confirms Patrick Barry, the sub-prior, "which people say is Becket's."
When Erasmus and John Colet, dean of St Paul's, visited Harbledown in 1514, they were unimpressed. "Why, by the same rule," sniffed Colet, when offered the relic to kiss, "they might offer his spittle or his dung." Embarrassed, Erasmus placed a generous donation in the chantry box.
Earlier pilgrims would barely recognise the approach to Canterbury itself. At the ring-road roundabout, however, the cathedral still rises up in the distance, towering over the modern city as it must have done over the medieval site. Around Christ Church Gate, the narrow lanes are still crammed with street-hawkers and sightseers. Along Burgate, the neo-Norman church of St Thomas displays its treasures in a glass case: a fragment of cloth, reputedly a piece from Becket's vestments, and what looks suspiciously like a walrus tooth - one of Becket's finger bones.
Uncharitably, Chaucer's pardoner, with his pillow cases and pig's bones, comes to mind. But in the cathedral crypt, Cherry Johnston, a volunteer exhibition attendant, explains the provenance of such relics. "When they moved the body up to the main church in the 1220s," she explains, "some bits fell off. These Becket's family were allowed to keep. You see, there's just so much of him left." Peering at a tiny exhibit the size and shape of a fingernail cutting, which is seemingly identical to the fragment of St Etheldreda at Ely Place, it is hard not to be sceptical. For the indefatigable Mrs Johnston, however, this is a piece of Becket's bone - a true relic of the cathedral's once-great shrine.
Yet somehow it does seem strangely moving that after 800 years, through all the religious upheavals of the Reformation and Cromwell's Protectorate - not to mention the terrible bombardment of the city during the last war - something of Becket, however small, however spurious, still remains at the spiritual centre of Britain. Despite the shrieks of school parties and the continuous bleep of the electronic tills in the souvenir shop (silver Becket charms £5.25), it is here, in the twilight of the crypt, that the footsteps of medieval pilgrims sound the loudest. !Reuse content