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 autopsy performed after his body was exhumed in 1901, and the 20th-century medical assessment is that his death is more likely to have resulted from uremia. The investigations in the 1990s have suggested that Tycho may not have died from urinary problems, but instead from mercury poisoning. It was speculated that he had been intentionally poisoned. The two main suspects were his assistant, Johannes Kepler, whose motives would be to gain access to Brahe's laboratory and chemicals, and his cousin, Erik Brahe, at the order of friend-turned-enemy Christian IV, because of rumors that Tycho had had an affair with Christian's