Built between the 14th and 17th centuries, the Château de Vincennes is the largest royal fortress still standing in France. Its 52-metre high keep, which protects the fortress and occupies one side of the courtyard, is one of the highest in Europe. It was the residence of Charles V and served as a royal prison from the 16th to the 19th centuries. Famous inmates include Nicolas Fouquet (1615-1680), Louis XIV’s superintendent of finance, and several writers – Denis Diderot (1713-1784), the Marquis de Sade (1740-1814), the Count of Mirabeau (1749-1791) – imprisoned by ‘lettre de cachet’. The keep has been listed as a historical monument since 1913.