The University of Würzburg was founded in 1402 by Prince-Bishop Johann von Eglofstein and is the oldest university in Bavaria and one of the oldest in German-speaking countries. Due to financial difficulties teaching was suspended from 1430 until 1551. In 1591, the university building commissioned by Prince-Bishop Julius Echter von Mespelbrunn was completed in the Neubaustrasse, now known as the „Alte Universität“. From 1629-1631 the Jesuit and mathematician Athanasius Kircher worked on physical problems. The start of modern physics in Würzburg was founded by Prof. Rudolf Clausius, who is regarded as one of the central founders of thermodynamics.