‘The interests and preoccupations of the “mad” Emperor Rudolf II in his castle fastness at Prague at one time seemed completely beyond rational understanding’, wrote Andrew Wheatcroft in his history of the Habsburgs. This was not entirely surprising. Rudolf exasperated both his family and the nobility. ‘His Majesty’, they declared, ‘is interested only in alchemists, wizards, cabbalists and the like.’ The papal ambassador at his court reported to Pope Clement VIII in 1600: ‘It is generally agreed amongst Catholics in Prague that the Emperor has been bewitched and is in league with the devil. I have been shown the chair in which His Majesty sits when holding conversations with the Prince of Darkness himself. I have seen the little bell His Majesty uses whenever he wishes to summon the spirits of the departed to do his bidding.’ Here is madness indeed – but whether the Emperor’s or the nuncio’s must be a matter of opinion.

Rudolf II, Holy Roman Emperor 1576–1617, was certainly one of the oddest members of his extraordinary family. ‘Gloomy, taciturn, bigoted and indolent’, according to the Chambers Biographical Dictionary, ‘he put himself in the hands of the Jesuits and low favourites, and left the empire to govern itself.’ An inaccurate