Christian Schroer takes over the scientific leadership of the synchrotron radiation source PETRA III. Previously, he was professor at Technische Universität (TU) Dresden, and after a joint appointment procedure of the University of Hamburg and DESY, he now assumes a professorship in Hamburg. Initially, he worked in the field of theoretical physics; after his graduation, Schroer specialised in nano research and the development of X-ray optics. He too has a professional past at DESY: Before he was appointed at TU Dresden, he worked as a scientist at DESY from 2004 to 2006. As new scientific head of PETRA III, Schroer will advance the scientific programme and considerably increase the portfolio of experimental techniques. Moreover, he and his new workgroup will further develop X-ray microscopy at synchrotron radiation sources and X-ray free-electron lasers.