Tycho improved the astronomical instruments, and created a well functioning observatory, Stjärnenborg, thus being able to make the very exact numerical observations that Kepler later used to develop his laws about the movement of the planets. His famous nose-job (rhinoplasty) was cosmetic, and the reason was that he lost part of the nose in a duel.
He died from drinking too much: His bladder exploded after a party at the court of Prague.