Astrology in the Renaissance court
A university subject, a court job, and the same men doing the astronomy.
2 min read · Published 2 September 2026
First, the answer
In Renaissance Europe astrology was taught in universities, practised at courts and built into medicine. Court astrologers timed military and political decisions, physicians consulted charts before treatment, and the same people often did serious astronomical work. The split between astronomy and astrology came later. It was not a feature of the period.
It was a profession
Astrology sat inside the university curriculum, usually next to medicine. Courts employed astrologers for practical work: electional advice on timing, horary answers to questions, natal readings for royal children. It had institutional standing, and calling it fringe superstition misdescribes how it worked.
The astronomers were the astrologers
Kepler cast horoscopes for income and criticised the trade while defending a version of it. Tycho Brahe and Galileo both cast charts. Casting a chart needs accurate planetary positions, so demand for astrology funded the observation that became modern astronomy, as it did in the Islamic world.
Kepler's horoscopes paid for Kepler's laws, and I'd count that as astrology's best investment.
Why it declined
No single refutation. Heliocentrism and Newtonian mechanics undermined the causal picture, astronomy professionalised separately, medicine adopted testable methods, and Enlightenment standards of knowledge left astrology outside the line. It lost standing across two centuries, so it survived culturally after losing the universities.
What survives
William Lilly's Christian Astrology of 1647 remains the reference for horary work, see the best books. And the vocabulary stayed: 'disaster' from ill-starred, 'influenza' from celestial influence, 'jovial', 'saturnine', 'mercurial', 'lunatic'.
Mira Hale