Marek Sergot is Professor of Computational Logic and Head of the Logic and Artificial Intelligence Section in the Department of Computing of Imperial College London. He graduated in Mathematics at Cambridge and then worked in mathematical modelling before joining the Logic Programming Group at Imperial College in 1979. His research is in logic for knowledge representation and in the formal specification of computer systems with particular interest in legal, temporal and normative reasoning and the logic of action. With Peter Hammond, he is the developer of the logic programming system APES which was used at more than 1000 sites throughout the world to build a wide variety of expert systems and other applications. With Robert Kowalski, he developed the ’event calculus’, an approach to reasoning about action and change within a logic programming framework, which is still one of the main standard techniques for temporal reasoning in AI. The formalisation of legal and normative reasoning, and its applications, has been a main topic of research since 1979. It has included contributions to the computer representation of laws and regulations, foundational studies in the logic of action and norms, formal theories of complex normative relations such as duties and rights, formal models of institutions and organisations, and applications to multi-agent systems, contracts, business processes, and computer security.