A secret world of magic, where mummified cats, bent pins, ancient symbols and patched shoes fight the forces of evil, will be uncovered at Norwich Castle this spring.

Eastern Daily Press: The brick with magical symbols found at Earlham Hall, Norwich.The brick with magical symbols found at Earlham Hall, Norwich. (Image: submitted)

And now, for the finishing touches to your lovely new home. Furniture, curtains, artworks, a bottle full of urine, human hair and nails.

Today we use locks, burglar alarms and timer-set lighting to protect our homes, but 300 years ago householders were not just worried about human intruders. They believed their homes were also at risk from supernatural forces – evil spirits, ill luck, ghosts and witches.

And so they buried magic charms in doorways, hid spells up chimneys and beneath fireplaces and protected roof spaces with dead animals.

Anywhere evil might enter a building, in a world beset by disease, failed harvests, disastrous fires and unexplained deaths, strong magic was needed.

Eastern Daily Press: A witch bottle found in Bury St Edmunds, containing the remains of rusty iron objects.A witch bottle found in Bury St Edmunds, containing the remains of rusty iron objects. (Image: Archant)

In Hethersett, near Norwich, a bottle with iron pins and nails was buried beneath a cottage fireplace. A dead cat was concealed in a room in King's Lynn, a horse skull was hidden under the doorstep of a house in Thuxton, near Dereham, and a jar of urine, human hair and nails was unearthed in King Street, Norwich.

These spells against supernatural harm were buried, bricked into walls, built into roof spaces, and experts in the beliefs behind the hidden charms say secrecy was part of their power to protect against demons, witches and curses.

Today witch bottles and mummified animals are still discovered during renovations and demolitions, and in April historians who specialise in this world of protective spells against the powers of darkness which seemed all too real to our ancestors will meet at Norwich Castle.

The practice of trying to turn away evil with magic charms and potions is called apotropaios and was common for centuries. In Britain it was particularly prevalent during the peak period of the witch trials in the 16th and 17th centuries, but was still seen into the 20th century.

Eastern Daily Press: A 16th-century Bellarmine jar found on the site of The Forum in Norwich.A 16th-century Bellarmine jar found on the site of The Forum in Norwich. (Image: COPYRIGHT ECN 1998)

Brian Hoggard, a historian who researches folk magic and runs a website called Apotropaios, is helping organise the conference to explore topics including the purpose of buried bottles, the practice of concealing shoes to repel evil, and the use of ritual protection marks and hidden charms across Britain and further afield.

'We chose Norwich because there's a huge amount of these objects in East Anglia,' said Brian.

He has been interested in archaeology from his teens and studied the history of witchcraft as part of his history degree. 'When I finished my degree I thought it would be exciting to start a research project to try and get a sense of the distribution and extent of the folk magic practices,' said Brian. 'That was back in 1999 so I've gathered an enormous amount of information since then.

'Buildings from the lowest to the highest have been shown to contain these protective measures. One of our conference speakers, James Wright, will be talking about marks which have been found in high status buildings including the Tower of London. Homes, businesses, churches, grand houses - all seem to have been in need of protection.'

Eastern Daily Press: The Red Cat of the Red Cat Hotel in North Wootton.The Red Cat of the Red Cat Hotel in North Wootton. (Image: submitted)

The magic came in the form of potions including iron pins and nails (of which witches and bad fairies were known to be frightened), animals believed to have special powers, and spells written in words on rolls of paper, or scratched in pictures and diagrams on walls.

Perhaps the most common hidden charms of all were old shoes – almost always patched and repaired, usually single, often a child's. This superstition dates back at least as far as the 14th century when Buckinghamshire rector, and unofficial English saint, John Schorn is said to have trapped the devil in a boot (and which is depicted on several Norfolk rood screens). More than 1,200 examples have been recorded with one of the earliest found so far hidden in Winchester Cathedral in 1308. And the practise survived into the 20th century. 'Modern shoes are fairly regularly encountered during repairs and maintenance. I had an example of a Nike trainer being found in the roof of a central London bank, deliberately placed,' said Brian.

In homes they were often placed on a ledge inside a chimney where it was thought they would trap bad spirits.

Hidden charms are generally found at entry and exit points, including the hearth which would have been open to the sky – and any supernatural harm circling the house, trying to gain access.

'Some houses have shoes, bottles, marks and cats all from the same period so it's clear there that there was a strong urge to protect,' said Brian. Others have been found with many layers of protection. Three witch-bottles were found mortared into the hearth of a grand house in Essex at a time when the mistress is known to have been very ill. 'Presumably it was believed she was bewitched,' said Brian.

Dead cats are another common find, sometimes positioned as if they are hunting. They were believed to have a sixth sense and might have been hidden, perhaps as a sacrifice to ward off bad luck and black magic.

Witch bottles are usually found beneath hearths or front-doors, but have also been uncovered from beneath floors and inside walls.

Around 200 have been recorded in England, dating back to the 16th century. More than half are grey stoneware bottles and jars called bellarmine, decorated with the faces of grim-looking bearded men. They were filled with the ingredients including iron pins and nails, human hair, urine, and sometimes small bones, thorns, pieces of wood and heart-shaped scraps of fabric.

Many hidden charms will still be concealed in homes and other buildings and people keen to search for magic charms in their own houses should try under floorboards or above lintels near doors, in walls and roofs, and around hearths and chimneys. 'Buildings from the 17th and 18th century frequently are found to contain hidden charms,' said Brian. 'By their very nature, these charms are concealed so we only find them by luck or during repairs or demolition. Many will have vanished without trace into builders skips or the antiques trade so they may have been far more common that we can imagine.

'Objects such as witch-bottles, dried cats, concealed shoes, horse skulls and written charms - amongst others - have all been found in buildings in East Anglia. These are mainly found during demolition, restoration or sometimes just by exploring the nooks and crannies of a building.'

And simply shining the beam of a torch obliquely across hearths or door lintels could reveal ritual marks carved into the stone.

'Most of the things we'll be talking about were concealed within buildings or utilise some kind of symbol magic,' said Brian. 'The secrecy was a powerful part of their defensive qualities.'

Secrecy and mystery still surrounds many of the hidden charms, even after they are discovered. Unlike superstitions such as up-turned horseshoes, which are displayed openly, it was thought that this magic lost its potency if uncovered and Brian said that even modern-day householders often don't want items removed or even discussed – perhaps because a vestige of those old beliefs still remains.

'Very often we find that extremely sensible, non-superstitious and professional people, will suddenly become very superstitious and acutely tuned-in to the supernatural when they find these objects in their home,' he said. 'One home-owner I worked with on a witch-bottle refused to allow the contents to be examined and insisted that the bottle be re-buried with a small ritual including myself and some nuns. Others have insisted that concealed shoes are returned to their find-spot and that cats be re-concealed. Personally, I am always very respectful when handling these objects and generally recommend that the objects be properly documented and photographed before being placed back into the building. Occasionally people wish to donate the objects to local museums or have them on display in their homes behind glass.'

The inaugural national Apotropaios conference, at Norwich Castle, is aimed at anyone with an interest in the subject, from academics to amateurs.

Shining the light of research on the spells, potions, charms and ritual marks hidden in homes across the county, country and even further afield, the conference will reveal some of our ancestors' darkest fears and deepest secrets.

• Hidden Charms, a conference exploring the magical protection of buildings, will be held in the Town Close Auditorium, Norwich Castle, from 9.30am to 5.30pm on Saturday, April 2. Tickets are £30 in advance or £35 on the door. For more information contact Brian Hoggard by calling 07720 211002 or emailing brianhoggard@ymail.com