Peter B. Karadakov received his M.Sc. in Chemistry from Sofia University, Bulgaria, in 1981, and his Ph.D. in Quantum Chemistry from the Bulgarian Higher Degrees Commission in 1983. After a lectureship at the Faculty of Chemistry of Sofia University and a research position at the Institute of Organic Chemistry of the Bulgarian Academy of Sciences, during which he was doing independent research on Hartree-Fock instabilities in extended systems and the spin-projected Hartree-Fock method, including the formulation of the “extended” pairing theorem, some of which was in collaboration with Jean-Louis Calais at the University of Uppsala, in 1990 he joined the research group of Joseph Gerratt at the University of Bristol to work on the development and applications of spin-coupled generalized valence bond (SCGVB) theory and many-electron spin functions. In 1995 PBK accepted a lectureship in Physical Chemistry at the University of Surrey where, through his collaboration with Graham A. Webb, he became interested in theoretical NMR, which led to another collaboration, with Keiji Morokuma, on the calculation of NMR shieldings with the ONIOM method. In 2001, PBK moved to the University of York. His research is equally shared between the development and applications of SCGVB theory and the use of off-nucleus NMR shielding to describe bonding, aromaticity, and antiaromaticity in the ground and excited states of molecular systems.