On Friday 15th February 2013, Judge Jean-Paul Costa, former President of the European Court of Human Rights, delivered the 2013 Sir David Williams Lecture entitled "The Relationship Between the European Court of Human Rights and National Constitutional Courts?". The Sir David Williams Lecture is an annual address delivered by a guest lecturer in honour of Sir David Williams, Emeritus Rouse Ball Professor of English Law and Emeritus Vice-Chancellor of Cambridge University. More information about this lecture, including photographs from the event, is available from the Centre for Public Law website at http://www.cpl.law.cam.ac.uk/sir_david_williams_lectures/