Prof David Khmelnitskii is a Senior Research Fellow of Trinity College and a member of the TCM group since January 1991. Before that, starting from 1968, he conducted research in the broad field of condensed matter theory in the Landau Institute of Theoretical Physics, Moscow. His accomplishments are associated with the renormalization-group theory of critical phenomena, effects of disorder on phase transitions, the Quantum Hall Effect and coherent phenomena in disordered conductors, including weak localisation, anomalous magnetoresistance and mesoscopic fluctuations. In 1993 he was awarded the Hewlett-Packard Europhysics Prize.