Special 2005 EPS HEPP prize colloquium

First evidence and measurement of direct CP violation by the NA31 experiment This is a colloquium celebrating the awarding of the 2005 EPS High Energy Particle Physics prize to Heinrich Wahl and the NA31 collaboration which showed for the first time Direct CP Violation in the decay of neutral K mesons. There will be an introduction to direct CP violation, followed by a review of experimental results.