Translations of Kepler’s Astrological Writings Part I. Kepler as Practising Astrologer Section 2. Kepler’s Clients Subsection 1. Kepler’s Methods of Astrological Interpretation for Rudolf II, 1602

After Tycho Brahe’s death in 1601, Kepler was appointed Imperial Mathematician (included in the job description: Court Astrologer) for the Emperor Rudolf II. It is clear that Kepler took his responsibilities as astrologer to the Emperor seriously. Interpretations of Rudolf’s natal chart are extant as well as delineations of his solar returns, transits and directions; Kepler performed these according to both ‘traditional’ methods and to his own preferred ones. In addition, the psychological implications of the interpretations on the Emperor also concerned Kepler, as is evident in a letter he wrote to an unnamed official in 1611. The next three sections cover, first, Kepler’s delineation of Rudolf’s natal chart, directions and solar returns by his preferred methods (these contain some theory as well); second, his interpretations by traditional methods; and finally his letter to the official. Note that, for reasons of clarity, we first translate the interpretation by Kepler’s preferred methods, though these follow the traditional methods in the text.