Jirí Krejcík was originally supposed to direct the film. But after few days of shooting and his constant fights with leading actor Jan Werich, he was replaced by Martin Fric.
According to Vera Chytilová, who later became a prominent name of Czech New Wave movement, her acting experience in this movie (she played one of the ladies in waiting) raised her desire to became a filmmaker.
The film fictionalizes the life of Rudolf II, Holy Roman Emperor (1552-1612, reigned 1576-1612). In real life, Rudolf was fascinated with the occult, with astrology, and with alchemy. He was a patron to well-known European alchemists such as Edward Kelley (1555-1597/1598) and John Dee (1527-1608/1609).
Karel Höger and Irena Kacírková were originally among the cast, as Kelley and Sirael, respectively. However, after change of the director, they were replaced by Jirí Plachý and Natasa Gollová.
Jana Werichová's debut.