Paul Hagenmuller, honorary professor at the Université de Bordeaux, passed away at the age of 95 on January 7, 2017. Hagenmuller was one of the founders of solid-state chemistry at the interface between chemistry, physics, and material science, with contributions including high oxidation states in transition metal oxides, magnesium hydride for hydrogen-storage applications, and synthesis of copper perovskites. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.