The chateau was built by the Lords of Joux in the 11 C, and was enlarged under Emperor Charles V. Vauban fortified it, in view of its vulnerable position near the border, after France annexed the Franche-Comte in 1678, and the fortress was used as a prison until 1815. The last modernizations were carried out between 1879 and 1881, by the future field marshal, Joffre. The stronghold has seen many political prisoners, military figures and other famous personalities pass through its gates. Mirabeau was shut up here after his father, tired of bailing his son out of the debts he ran up with his profligate lifestyle, succeeded in obtaining an order under the King’s seal to lock him up out of the reach of moneylenders. Toussaint Louverture, a black politician who played a major role in the fight against slavery in France, earned Napoleon’s displeasure with his efforts to win independence for Haiti and was imprisoned in Joux in 1802. He died of a lung infection a couple of months later, thus missing the proclamation of Haitian independence read out by Dessalines on 1 January 1804. The German writer Heinrich von Kleist was also held here on charges of spying in 1806.