When Tory leader David Cameron opened the British Museum's new medieval gallery earlier this year, he made a rather torturous reference in his speech to the similarities between the present day and the medieval period: financial crisis, political upheaval and unpopular governments.

But there are more obvious connections between the two periods: climate change, virulent disease and warfare to name just a few. Whatever the links between now and then, this year has marked a renewed interest in the medieval period with the opening of several new galleries and the redisplay of collections.

In March the British Museum opened its Gallery of Medieval Europe; in August English Heritage unveiled its £2.45m reinterpretation of the Great Tower at Dover Castle; and next month London's Victoria and Albert Museum (V&A) will open its £30m Medieval and Renaissance Galleries.

Despite all this activity scholars and curators agree that for the public it is one of the least understood periods of British history. James Robinson, the curator of late medieval Europe at the British Museum, says misconceptions are rife.

"Preconceptions of the period are that it's all pestilence, death, disease and ignorance - we wanted space and light in the galleries and to look at the positive achievements of the middle ages. History is about building blocks - without the medieval you wouldn't have the Renaissance."

How then to interpret the vast era covering more than 1,000 years of history to an uninformed public audience? Scholars can't even agree on when the period began or ended or on terminology - no wonder the average member of the public is confused.

The starting point has been research, of the collections and the buildings, but most importantly visitor research: what do and don't visitors know?

Stuart Frost, a gallery educator at the V&A, was seconded to the Medieval and Renaissance Galleries project at an early stage and part of his role has been as an audience advocate. He says extensive visitor research shows that people's understanding of the period is very poor.

"There are a host of misconceptions. It's a difficult period to locate and it also has negative connotations. When people imagine the medieval world it's all rain and plague and suffering and nothing changes. There's no innovation and it's crafts people not artists."

As part of the research, visitors were asked to look at a selection of medieval and Renaissance objects and pick the ones that were interesting and the ones that they reacted negatively to.

Overwhelmingly they described medieval art as flat and stylised and found it difficult to accept as art. Frost says they were more comfortable with Renaissance art and its recognisable human forms.

Visitors also tended to view the two periods as opposites: medieval being dark and crude and the Renaissance full of light and artistic achievement. The challenge for the V&A was to dispel these false impressions.

"Knowing what visitors knew really did inform the design," says Frost. "One of the principles was to try to get light into the galleries. People tend to think they are two distinct periods, which brought out the need to bring the two periods together."

For Peta Motture, chief curator of the Medieval and Renaissance Galleries at the V&A, the objects are the key: "Having medieval and renaissance together shows the continuity. We hope visitors will get sucked into the space by objects."

And it's some space: 10 galleries, covering 3,250 sq metres, and holding 1,800 objects. It is the largest V&A project since the reopening of the British Galleries in 2001.

Motture says each gallery will have a theme and can be viewed separately. "If you want to start the story from the beginning you can, but there are several entrance points depending on which way you come in. We know it's a vast story, we know visitors get tired, so each room has one narrative, date, time and story."

Complementary exhibitions

The British Museum, V&A and the Museum of London - which redid its medieval gallery in 2005 - have all shared research, but the end results are very different. According to Robinson at the British Museum this is because the collections define the displays, and each institution wanted to complement the others' approach.

"There are broad themes: the Museum of London has a strong archaeological collection, the V&A is design and art led, and at the British Museum we can pull together art alongside archaeology. If visitors went to each of the London museums I hope they wouldn't feel the experience had been duplicated."

In the British Museum's medieval gallery the displays have been thinned down, a process that Robinson describes as "painful" from a curatorial point of view.

"Doing that has meant we have been able to make things sing out. For our visiting audience it has been a huge success. People have been queuing up to read the labels and dwelling much longer in the gallery."

But what if you don't have a collection? For Historic Royal Palaces (HRP), English Heritage and the National Trust, reinterpreting medieval buildings without pre-existing collections has provided a new set of challenges.

Jane Spooner, the historic buildings curator at the Tower of London, says visitor research showed that most visitors didn't understand the medieval palace as a residence for Henry III and Edward I. "Very few people who came to the tower had heard of the two monarchs and they didn't understand the idea of itinerant kingship."

Previous displays had recreated interiors that had been deliberately "distressed" to make them look old. This time HRP went for a different approach. One room has been left as what Spooner describes as an "archaeological palindrome" where visitors are shown what evidence was used to recreate other parts of the palace.

The recreation of Edward I's bed chamber, for example, was based on financial accounts that record a payment of 11s and 1d for timber, boards and panels for a bed for the king, and for transporting it through England.

Spooner says this piece of information was the starting-point for recreating Edward's bed and some visitors have been shocked by the flashy results.

"Royalty liked bright colours, it's not a post-18th-century idea of good taste. Also they didn't just stay in one castle - all the furniture could be packed away, it was all portable. There are no 13th-century beds surviving so we had to combine archaeological evidence and royal accounts."

The House of Bling

Having very little in the way of objects has also led to a creative approach to interpretation at Dover Castle. Edward Impey, director of research and standards at English Heritage, believes visitors will be surprised by the four new rooms in the Great Tower, which opened in August.

And he adds that if people are surprised it's not because the representation is wrong, it's because people don't know enough about 12th-century interiors.

Four interiors have been recreated from scratch: a royal suite, royal guest room, kitchen and armoury. It was a mammoth task considering that there was no inventory, descriptions or objects from the period. Kitting out the four rooms involved 140 craftsmen, from blacksmiths to needleworkers, who created 1,300 objects in total.

Impey admits the colour scheme, rich golds, reds and blues, could be described as "bright and vulgar". But he says it is the result of an "enormous" research project and that conservation principles have been adhered to.

Impey says he wanted to capture the significant moment in time, when the palace was doing the job that it was built for. "We wanted to evoke the appearance of how it might have looked on a great royal occasion. We know from records a lot about the people in the household; the idea was to bring people alive as well as the building."

Curators at Tattershall Castle, a 15th-century red-brick National Trust property in Lincolnshire, also took a radical approach to interpreting the building over the course of the summer. As part of an Arts Council England scheme to develop arts-based projects in historic houses, artists were commissioned to produce works for the castle.

The result was a temporary exhibition, the House of Bling (8-23 August), which showcased the work of six artists, both inside and outside the building. Jane Greenfield, co-curator of the exhibition, said she was drawn to the fact that it was a huge building with empty spaces.

"Understanding the medieval history of the castle was central to reinterpreting it. The artists researched the history of the castle and the family."

But she says it was the National Trust that coined the House of Bling phrase. "It was so we could see how the person who originally built the castle did it as a statement of his wealth to say: 'Look how rich I am.'"

By the time the Medieval and Renaissance Galleries at the V&A open next month anyone interested in medieval art and history will have a vast array of galleries and buildings to choose from to further their knowledge.

This is no bad thing considering the V&A's own research shows that visitors' perceptions of the period derive from sources as diverse, and historically inaccurate, as BBC comedy series Blackadder and the film Braveheart.

For Jane Spooner, it doesn't matter where the renewed interest has come from so long as it's there. "This renaissance has been a long time coming. It's taking the medieval period out of scholarly hands and is widening its appeal."

History lessons

Gallery of Medieval Europe, British Museum, London

Opened: March 2009
Cost: £2m
Funders: Paul and Jill Ruddock
Curator: James Robinson
3d design: Softroom
Graphic design: Jade Design
Architect: BDP
Graphic production: Service Graphics, Halcyon Design, Mash
Lighting: Lighting Services Partnership, Erco, DHA
Fit-out: Coniston, Marzorati Ronchetti, The Hub
Display cases: Glasbau Hahn
Object mounting: Colin Bowles, Heritage Tile Conservation

Great Tower, Dover Castle, Kent

Opened: August 2009
Cost: £2.45m
Main funders: Sea Change (programme to regenerate seaside resorts), English Heritage
Project director: Edward Impey
Exhibition design: Hayley Sharpe
Lighting design: Sutton Vane
Pepper's ghosts: Integrated Circles

Medieval and Renaissance Galleries, Victoria and Albert Museum, London

Opening: November 2009
Cost: £30m
Main funders: Heritage Lottery Fund £9.75m, Paul and Jill Ruddock; Garfield Weston Foundation; Monument Trust; Simon Sainsbury; Wolfson Foundation; Edwin and Susan Davies OBE; Hintze Family Charitable Foundation; Selz Foundation; Foyle Foundation; Robert H Smith
Chief curator: Peta Motture
Project director: Moira Gemmill
Exhibition design: MUMA
Graphic design: Holmes Wood
Lighting: Arup Lighting, DHA Design
Display cases: Glasbau Hahn
Contractor: Holloway White Allom