César Augusto Gaviria Trujillo (Spanish: [ˈsesaɾ awˈɣusto ɣaˈβiɾja tɾuˈxiʝo] ; born 31 March 1947) is a Colombian economist and politician who served as the President of Colombia from 1990 to 1994, Secretary General of the Organization of American States from 1994 to 2004 and National Director of the Colombian Liberal Party from 2005 to 2009. During his tenure as president, he summoned the Constituent Assembly of Colombia that enacted the Constitution of 1991.