Complex sentence: He taught at Harvard University and the University of Illinois, and then at the Sorbonne in Paris, the University of Strasbourg in Strasbourg, France, Johns Hopkins University and the University of Vienna in Vienna, Austria.
Split into simpler sentences: He taught at Harvard University and the University of Illinois, and then at the Sorbonne in Paris, and the University of Strasbourg in Strasbourg, France. He was then a lecturer at Johns Hopkins University and at the University of Vienna in Vienna, Austria.