25th Anniversary of ICTP's Dirac Medal. ICTP has celebrated the 25th anniversary of its Dirac Medal on 10 November 2010 with a day of lectures by past and present medal winners, covering a vast range of topics in theoretical physics. This day-long series of lectures by past and present Medallists, covering a vast range of topics in theoretical physics, is made available here. -- NOTE: This conference was recorded automatically in slots of one hour and processed without human intervention. Lectures may be split between videos; their starting time may not coincide with the beginning of videos and intervals were not removed.