Hermann Schlichting is one of the internationally leading scientists in the field of th fluid mechanics during the 20 century. He contributed largely to modern theories of viscous flows and aircraft aerodynamics. His famous monographies Boundary Layer Theory and Aerodynamics of Aircraft are known worldwide and they appeared in six languages. He held Chairs of Aerodynamics and Fluid Mechanics at Technische U- versität Braunschweig during 37 years and directed the Institute of Aerodynamics of the Deutsche Forschungsanstalt für Luftfahrt in Braunschweig. He also directed the Aerodynamische Versuchsanstalt Göttingen and served in the Executive Board of the German Aerospace Center (DFVLR). Hermann Schlichting played a leading role in the rebuilding of aerospace research in Germany after the Second World War. th The occasion of his 100 birthday in the year 2007 was an excellent opportunity to acknowledge important ideas and accomplishments that Hermann Schlichting c- tributed to science. The editors of this volume are the present successors of Hermann Schlichting in his role as director of the two research institutes in Braunschweig. We were glad to host a scientific colloquium in his honor on 28 September 2007. Invited former scholars of Hermann Schlichting reviewed his work in boundary layer theory and in aircraft aerodynamics followed by presentations of important research results of his institutes today.