In the late 16th century the greatest philosophers, alchemists, astronomers, painters, and mathematicians of the day flocked to Prague to work under the patronage of the Holy Roman Emperor Rudolf II, an emperor more interested in the great minds of his times than in the exercise of his immense power. Rarely leaving Prague Castle, he gathered around him a galaxy of famous figures: among them the painter Arcimboldo, the astronomer Tycho Brahe, the...