The château at Ferney recently reopened to the public after three years of restoration and refurbishment. Except for the planes high above the lawns, flying in and out of Geneva airport, not much has changed at the château since Voltaire lived here between 1760 and his death in 1778. It’s easy to imagine him taking an afternoon stroll among the plane trees, Mont Blanc in the background, after a morning in bed dictating his voluminous correspondence to his private secretary. During his twenty years at Ferney, he wrote 6000 letters.

When Voltaire first visited, Ferney was a small village of 130 inhabitants, but it had at least one advantage to a polemicist used to falling out with the authorities: its strategic location just on the French side of the border with the republic of Geneva. Frederick the Great had recently chased Voltaire out of Berlin, and he was still unwelcome in Paris. (In his youth he had twice been imprisoned in the Bastille: for insulting the prince regent in 1717, and for challenging the Chevalier de Rohan to a duel in 1726.)

With the help of Swiss friends – notably the Cramer brothers, who later published the Poem on the Lisbon Disaster and Candide – Voltaire had settled in Geneva in 1754. Printing houses had flourished in the protestant city state, out of the reach of royal censors, but theatre was forbidden and after a few years Voltaire moved on.

The last words of Candide, ‘Il faut cultiver notre jardin,’ are often interpreted metaphorically, but Voltaire took them literally enough. He sold his garden produce in Geneva and at one point even considered building a harbour to expand his trade. ‘A hangout of 40 savages has become an opulent town,' he wrote, 'inhabited by 1200 useful souls.’ He drained swamps, planted potatoes, bought a seed drill and boasted to his Parisian friends of ploughing the fields himself. In his letters, he enjoyed referring to himself as a ‘farmer’ or ‘rural philosopher’.

Voltaire invited clockmakers from Geneva, the descendants of French protestants who had sought asylum in the city, to open workshops in Ferney. Bewildered spies from both France and Switzerland reported on the oddity of Catholics and Protestants living in harmony together. Voltaire sold clocks all over Europe. He once sent Catherine the Great twice as many watches as she’d ordered, then complained when her payment was 200 rubles short.

Voltaire often complained about being sick, and about Ferney’s long winters, signing his letters ‘the old hermit from Mount Jura’, but he wasn’t much of a hermit. Condorcet, d’Alembert, Pigalle and Denon were among the many intellectuals who stopped at Ferney for a few days en route to Italy. Voltaire would often have sixty or more guests to dinner, and organised plays, concerts and chess games.

He didn’t retreat from the world. When Jean Calas was falsely accused of killing one of his sons in Toulouse – French Protestants were suspected of violence towards children who wanted to convert to Catholicism – Voltaire took up his cause. After Calas’s execution, Voltaire invited some of his family to Ferney. The case inspired him to write the Treaty on Tolerance, which was a worldwide bestseller as recently as in 2015, in the wake of the Charlie Hebdo attack.