Socialism with a human face (Czech: socialismus s lidskou tváří, Slovak: socializmus s ľudskou tvárou) was a slogan referred to programme of Alexander Dubček and his colleagues agreed at the Presidium of the Communist Party of Czechoslovakia in April 1968, after he became chairman of the Party in January 1968. The first author of this slogan was Radovan Richta. It was a process of mild democratization and political liberalization that sought to build an advanced socialist society that valued democratic Czechoslovakian tradition. It would still enable the Communist Party to maintain real power. It initiated the Prague Spring which, on the night of 20-21 August 1968, was stopped by the Warsaw Pact invasion of Czechoslovakia.