Scientists all over the world know Gottfried Landwehr as Mister High Magnetic Field. In 1972, he started the conference series ``The Generation of High Magnetic Fields and their Application in Solid State Physics'' and acted as the director of the High Magnetic Field Laboratory in Grenoble at the time when the Quantum Hall Effect was discovered at this research center. His scientific interest in low temperature physics and semiconducting materials (mainly low dimensional electron systems) together with his strong connections to the Metrology Institute in Germany (Physikalisch Technische Bundesanstalt, PTB) formed the basis for scientific breakthroughs and discoveries with the Quantum Hall Effect as the main highlight. There is no doubt; he is the Grandfather of the Quantum Hall Effect.

I have known Gottfried Landwehr for more than 40 years, and first met him in Braunschweig at the PTB, where I worked as a summer student. Gottfried Landwehr had the privilege to run the ``Laboratory of the President'' which allowed him to do basic research within an excellent scientific environment. His main interests were magnetotransport phenomena in semiconductors such as germanium, tellurium and III/V semiconductors in pulsed magnetic fields up to 10 Tesla. His investigations on germanium bi-crystals opened the research field of low-dimensional electron systems, since the hole accumulation at the grain boundary between the crystals forms a two-dimensional hole gas. The accidental observation that (depending on the etching process) a two-dimensional hole gas can be formed not only at grain boundaries but also at the surface of an undoped tellurium crystal led to a concentration of Gottfried Landwehr's research into the field of two-dimensional electron systems. A fruitful cooperation with Gerhard Dorda at the Siemens Research Laboratory extended the research program in the direction of modern Silicon field effect transistors with pioneering transport research on n- and p-channels with different surface orientations. Even today, low-dimensional systems are one of the topics of his scientific research. Especially II/VI semiconductors with their applications as blue lasers or in spintronic are connected with the name Gottfried Landwehr. All these research activities have contributed to the topics of the international conferences ``New Phenomena in Mesoscopic Structures (NPMS)'' and ``Surfaces and Interfaces of Mesoscopic Devices (SIMD)''. In recognition of Gottfiied Landwehr's contribution to science and to the scientific community, the special joint mesoscopic conference NPMS/SIMD 2005 was dedicated to him.