By 1328, the medieval Christian heresy now referred to as Catharism had been all but destroyed. After the fall of Montségur in 1244 and the fortress of Quéribus in 1255, the remaining Cathars were driven back into the high valleys of the Pyrenees. Many Cathar priests – parfaits and parfaites - were executed, or driven into Lombardy or Spain.

Despite this, the early fourteenth-century saw a remarkable renaissance of Cathar communities in the upper Ariège, principally around Tarascon and Ax-les-Thermes (then known as Ax) and key villages, such as Montaillou. The Inquisitional Courts in Pamiers (for the Ariège) and Carcassonne (for the Languedoc) continued to persecute and hunt down the heretics (as they were considered). Those taken were imprisoned in dungeons known as Murs. Principal in this was Jacques Fournier, a Cistercian monk, who rose quickly through the Catholic ranks, becoming bishop of Pamiers in 1317, of Mirepoix in 1326, a cardinal in 1327, and, finally, Pope in Avignon in 1334, as Benedict XII. It is an irony that Fournier’s Inquisition Register, detailing all interrogations and depositions made to the courts on his watch, is one of the most important surviving historical records about Cathar experience in fourteenth-century Languedoc. The last Cathar parfait, Guillaume Bélibaste, was burnt at the stake in 1321.

During the vicious final years of the extermination of the Cathars, whole villages were arrested – such as at Montaillou in the spring and autumn of 1308. There is evidence that entire communities took refuge in the labyrinth network of caves of the Haute Vallée of the Pyrenees, the most infamous example being in the caves of Lombrives, just south of Tarascon-sur-Ariège. Hunted down by the soldiers in the spring of 1328, hundreds of men, women and children fled into the caves. The soldiers of the Inquisition realised that, rather than continue to play cat-and-mouse, they could use traditional siege tactics and block the entrance, bringing the game to an end. This they did, entombing everyone inside in some kind of medieval Masada.

It was only 250 years later, when the troops of the Count of Foix-Sabarthès, the man who was to become King Henry IV of France, excavated the caves that the tragedy was revealed. Whole families were discovered – their skeletons lying side by side, bones fused together, their last precious objects beside them – and finally brought down from the stone refuge that had become a living tomb.

It is this grisly fragment of Cathar history that was the inspiration for The Winter Ghosts. The village of Nulle does not exist.

For those readers who want to know more about the final days of Catharism, Emmanuel Le Roy Ladurie’s classic Montaillou, first published in 1978, is the most complete and detailed explanation of the complications of life, faith and tradition in fourteenth-century Ariège. De l’Héritage des Cathares (available in translation as The Inheritance of the Cathars) by the French mystic and Tarasconais Cathar historian of the 1930s and 1940s, Antonin Gadal, is well worth dipping into. René Weis’ The Yellow Cross: The Story of the Last Cathars 1290-1329, Anne Brenon’s Pèire Authier: Le Dernier des Cathares and Greg Mosse’s Secrets of the Labyrinth are all excellent.

Kate Mosse Toulouse, April 2009

Kate Mosse is an author and broadcaster. Her best-selling books include, amongst others, Labyrinth and Sepulchre. Kate is the Co-Founder and Honorary Director of the Orange Prize for Fiction and in 2009 was invited to be an Ambassador for the Aude Tourist Board, the region of France where much of her fiction is set. Kate lives with her family in Chichester and Carcasonne.

It was so cold in Paris in January 1891 that the beggars on the streets, the vagabonds and working girls in the Place Clichy said that the sun had died.

The Seine froze over. The poor and the homeless were dying, which prompted the reluctant authorities to open shelters in gymnasiums, shooting galleries, schools and public baths. The biggest dormitory was in the Palais des Arts Libéraux in the Champs-de-Mars, in the shadow of Monsieur Eiffel’s magnificent tower. Intended to symbolise all that was splendid, patriotic, modern about the Third Republic, the metal structure instead found itself presiding over dull, dark and soundless winter days. Masses of people huddled like refugees, fugitives from the cold. The scenes were reminiscent, the shopkeepers said, of the dark days of the Franco-Prussian war when German boots marched in the Champs-Elysées.

George Watson, formerly of the Royal Sussex Regiment, thought back to his own fighting days, to the heat of the Transvaal in December 1880, when they had subdued the uprising. Three months from start to finish. He had spent his twenty-first birthday with a rifle in his hand.

Throughout France the story of this winter was the same. In Carcassonne, in the foothills of the Pyrenees, the River Aude burst its banks sweeping away the most vulnerable quartiers of Trivalle and Paicherou. In the Ariège, the villages were locked in by ice and snow. Even in England, he read in an edition of The Times some seven days old, a great blizzard had swept through the south in the spring.

Nature was fighting back.

But, for George Watson, 1891 was a year of wonder. It was a year of unaccustomed experiences. He arrived in Paris in the pale and wet spring, which came late that year, and stayed during the brief, bullying heat of summer. His father had died the previous year – a hero of Khartoum, he had received a full soldier’s send off – and George would soon have to take up his new responsibilities in England. But, for a few months, he was a free man. He was in France to come to a decision about his future and was in no hurry. Having resigned his commission, George set about transforming himself from a soldier into a flaneur, an artist, a philosopher. He had nothing in common with the poets and the artists and composers about whom he read in the newspapers, and he knew it, but he was determined to dip his toe in the water and fully experience the alternative, teeming, headlong metropolis that was Paris.

His father had not approved of opera. Now the old man was dead, George intended to make up for the lost years of music by attending every opera for which he could acquire a ticket. He was there at the premiere of Massenet’s Griselde, though found the bawdy tunes of Bizet’s Carmen more to his liking. He saw Meyerbeer’s Les Huguenots, Donizetti’s Don Giovanni, Rossinni’s William Tell, Ambroise Thomas’ Hamlet, Halèvy’s La Juive and Gounoud’s Faust. And, though it was not all to his taste, he found himself infected by what they were calling the fin-de-siècle spirit. As George sat with his gloves and his top hat in the Palais Garnier, admiring the feathered adornments and white skin of the ladies around him, he vowed that he would never forget what it was to be young. How he would treasure these memories as stories to tell his children in years to come. How at the Comédie-Française passions stimulated by Thermidor, Victorien Sardou’s violently anti-Robespierre play, had been so intense that the Minister of the Interior had been forced to ban performances. How, when Wagner’s Lohengrin was staged at the Palais-Garnier, it was whistled and booed off stage, just as Tannhaüser had been some thirty years earlier.