Charles was appointed Permanent Secretary of the Ministry of Education, Sports and Culture and held that position from January 1981 to December 1985.
Charles served as an Advisor on Special Programs to the Organization of Eastern Caribbean States from June 1986 to October 1995.
In November 1995, he became the UNESCO Educational Advisor in Pretoria, South Africa, serving until April 1998.
In June 1998 he became the UNESCO Representative and Head of Office in Maputo, Mozambique, serving until December 2000.
Finally, in January 2001, he became the UNESCO Representative and Director of the Office for the Economic Community of West African States, serving in Abuja, Nigeria until October 2006.