Tycho Brahe (1546–1601), despite being a Danish nobleman, turned to astronomy rather than politics. Granted the island of Hven in 1576 by King Frederick II, he established Uraniborg, an observatory containing large, accurate instruments. At the time, Uraniborg was the most technologically advanced facility of its type ever built. Brahe’s measurements of planetary motions, therefore, were more precise than any that had been previously obtained. This facility and these measurements helped Brahe’s protégé, Johannes Kepler, determine the elliptical nature of the motion of planets around the Sun.