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
Tadeáš Hájek is unfortunately lost now. In 1564 he received the Emperor's privilege stating that no astrological prognostication could be printed in Prague before he had seen and approved it. In 1566–1570, he served as an army doctor in Austria and Hungary during the war with the Ottoman Empire. He published his studies of a supernova in the constellation Cassiopeia in 1572. Tadeáš Hájek was in frequent scientific correspondence with the recognized astronomer Tycho Brahe (1546–1601) and played an important role in persuading Rudolph II to invite Brahe (and later Kepler) to Prague. His voluminous writings in Latin were mostly concerned with