It's Christmas at the National Trust as houses across the country get ready for the most magical time of the year. As the countdown to Christmas begins, the teams at three unique National Trust houses race against the clock to deck their halls in time for three spectacular festive openings, each with a different theme.

High up on the Northumberland moors is Cragside, a Victorian arts and crafts mansion. Each year, the team takes inspiration from their history to prepare a magical festive experience for visitors, and this time they are getting set to present the Servants' Ball - traditionally the one night of the year when the servants were allowed the run of the house.

Overlooking the Tamar Valley, Cornwall's Cotehele is one of the best-preserved Tudor houses in the country. Every spring, the gardeners begin collecting and drying thousands of flowers from the estate in preparation for building a 60-foot Christmas garland.

Finally, in south Devon's famous arts and crafts house Coleton Fishacre, the team is celebrating the property's centenary with a roaring 1920s-themed party, which promises all the glitz and glamour of a Christmas night out.

A look at the homes of two families who battled to defend their beliefs and the divinely inspired masterpieces they contain.

In the shadow of Bodmin Moor lies the grand Jacobean mansion Lanhydrock, the family seat of the Robartes family. Its grand long gallery, a 17th-century survival of a 19th-century fire, is undergoing a huge conservation project, with every single square centimetre of the ceiling requiring cleaning, stabilising and repainting.

In Warwickshire, an even larger conservation project is in progress. At Tudor manor Coughton Court, the very fabric of the building needs essential work, without which the historic collection inside the house is at risk. A specialist team are on site to preserve, repair and improve the roofs and facades of the building.

Meanwhile, a rare Catholic treasure from the house's collection - the Tabula Eliensis, a unique painting of the coats of arms of Catholic gentlemen interned by Elizabeth I - needs to be sent away for essential conservation. The roof project has presented a unique opportunity: using a crane to hoist the tabula out and up into the air through a tiny slot cut in the ceiling before the new roof is in place.

A look at the homes of three men who changed British life through art, culture and architecture.

In Hampstead lies the former home of architect Erno Goldfinger, a pioneer of postwar high-density housing and the creator of many iconic buildings, such as the Trellick and Balfron towers in London. His collection of avant-garde art aimed to complement his designs for modern living, but a piece by Argentinian artist Hugo Demarco is in need of conservation work.

At Upton House, the 1930s country retreat of art lover and National Gallery chair Walter Samuel, Lord Bearsted, major work is needed on one of the highlights of his collection, Tintoretto's The Wise and Foolish Virgins. And a mysterious letter has recently been donated to the collection at Carlyle's House in London, revealing how sought-after the company of literary giant Thomas Carlyle and his wife Jane really was.

A look at the battle to save the homes of two formidable women who refused to bow down to the enemies at their gates but who suffered very different fates after the English Civil War.

In west London, on the banks of the river Thames, sits one of the grandest Stuart residences in England – Ham House. Ham was home to Elizabeth Murray, who would become the Duchess of Lauderdale. From a staunchly Royalist family, she was able to find personal favour with Cromwell while secretly supporting the future Charles II. Richly rewarded for her loyalty, many of her most prized possessions are in desperate need of repair and conservation.

Watching over the Purbeck Hills in Dorset are the remains of Corfe Castle, home to another set of Royalists - the Bankes family - who suffered a very different fate. Lord Bankes's wife, Mary, is said to have personally defended the castle against Parliamentarian forces until a traitor in her ranks let the besiegers in. Now, the National Trust are undertaking their biggest ever conservation project at the castle.

Kedleston Hall was once home to Lord Curzon, the viceroy of India at the height of the British Raj. The famous Peacock Dress - named for the embroidered peacock feathers that cover it - can be found in Kedleston's collection. Famously worn by Lord Curzon's wife, Mary, it's now in dire need of repair.

Meanwhile, at the baroque mansion of Dryham Park in Gloucestershire, conservation work is needed on a rare but damaged painting of the port of Bridgetown, Barbados, which belonged to 17th-century colonial bureaucrat William Blathwayt. Barbados at the time was the centre of sugar production and intrinsically linked with the horrors of slavery, and the painting is thought to show an important but unknown event in the island's history.

The compelling and sometimes scandalous family stories behind two very different National Trust houses are revealed.

In Knole House, the sprawling Tudor ancestral seat of the Sackville family, a life-size nude statue of 18th-century ballet dancer Giovana Zanerini, commissioned by her lover John Frederick, is being conserved to slow the aging process and restore her legendary looks. Two other heirlooms at Knole - a set of 400-year-old rolled-up animal skin parchments - are so delicate that they haven't been unrolled for many years.

At the traditional Lake District farmhouse Townend, a key part of the archive of the Browne family of yeoman farmers - a bound volume of 18th-century letters - is being conserved using traditional book-binding skills, and scientific paint analysis has revealed the house's original Victorian paint scheme.

In this episode, the houses that became retreats, and places of inspiration, for three literary legends. 

At Hill Top, the countryside escape of Beatrix Potter, a collection of over 70 miniature pieces under the roof of Beatrix's own dolls' house is undergoing major conservation before a new exhibition. 

The tiny woodland cottage of Clouds Hill, Dorset, was a refuge for TE Lawrence, popularly known as Lawrence of Arabia. In the sparsely furnished upstairs room, a portrait of a young soldier on a Cornish beach has sparked debate on whether it portrays Lawrence himself. 

Lamb House in Rye was the home of celebrated Victorian writer Henry James, who wrote many of his greatest later works in the house's Green Room. Today, James's writing room is looking a little off-colour, and a damp problem means the walls are in urgent need of replastering and repainting.