Tycho Brahe as some had believed in his time. Tycho was born as heir to several of Denmark's most influential noble families and in addition to his immediate ancestry with the Brahe and the Bille families, he also counted the Rud, Trolle, Ulfstand, and Rosenkrantz families among his ancestors. Both of his grandfathers and all of his great grandfathers had served as members of the Danish king's Privy Council. His paternal grandfather and namesake Thyge Brahe was the lord of Tosterup Castle in Scania and died in battle during the 1523 Siege of Malmö during the Lutheran Reformation Wars. His maternal grandfather
Tycho Brahe "Rudolphine Tables". Also at the court in Prague was the mathematician Nicolaus Reimers (Ursus), with whom Tycho had previously corresponded, and who, like Tycho, had developed a geo-heliocentric planetary model, which Tycho considered to have been plagiarized from his own. Kepler had previously spoken highly of Ursus, but now found himself in the problematic position of being employed by Tycho and having to defend his employer against Ursus' accusations, even though he disagreed with both of their planetary models. In 1600, he finished the tract "Apologia pro Tychone contra Ursum" (defense of Tycho against Ursus). Kepler had great respect for