Tycho Brahe personalities. When Tycho and Vedel returned from Leipzig in 1565, Denmark was at war with Sweden, and as vice-admiral of the Danish fleet Jørgen Brahe had become a national hero for having participated in the sinking of the Swedish warship "Mars" during the First battle of Öland (1564). Shortly after Tycho's arrival in Denmark, Jørgen Brahe was defeated in the Action of 4 June 1565, and shortly afterwards died of a fever. Stories have it that he contracted pneumonia after a night of drinking with the Danish King Frederick II when the king fell into the water in a Copenhagen
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