One of the highlights of the Diet of Presburg in 1468 was a debate between two Polish astrologers, Martin Bylica and Jan Stercze. At issue was the proper interpretation of a geniture that Stercze had calculated in 1467 for János Rozgon, a Hungarian Count. Upon reviewing the geniture. Bylica declared that Stercze’s interpretation was founded on erroneous astrological principles. Stercze defended his interpretation in a series of letters to Rozgon, but the matter remained unresolved until the Diet of Presburg the following year. In front of the Hungarian king Matthias Corvinus and the rest of the Diet, Bylica and Stercze publicly debated the proper astrological techniques and the appropriate methods of interpretation. Corvinus judged the dispute and in the end declared Bylica the winner. Bylica was awarded 100 florins and, more importantly, became Corvinus’s principle astrologer and political advisor — a few years later, Bylica boasted that the king consulted with him on all important matters and rarely traveled without Bylica by his side. Stercze, by contrast, appears to have spent the remainder of his life in a small town in Transylvania.
This debate provides a glimpse of the social and politic context for Renaissance astrology. The dispute between Bylica and Stercze spilled out of the erudite circles of academically-trained astrologers and into the powerful world of royal politics. The fact that their contest was an important event at the diet in 1468 locates their astrology at the center of Corvinus’s politics. It also suggests that the practice of astrology included public performance. Unlike academic disputes, which were tightly circumscribed by rules, court disputes were governed by the intellectual and aesthetic interests of the prince. To succeed in the courtly arena required erudition and showmanship. Bylica had mastered both. It is no surprise that he was handsomely rewarded with Corvinus’s generous patronage for the remainder of his life.