Happy Birthday Mr President

President Yahya Jammeh of Gambia claims to have invented a cure for Aids, and has declared himself a hero of agriculture and development.

He is also known for his extravagance, where he celebrates in style.

Yahya Jammeh has maintained a firm grip on power since taking over with a military victory in 1994.

His critics accuse him of being dictatorial, and human rights groups say he has suppressed opponents and the free press in Gambia.

For Assignment, Ed Butler visits Gambia and examines the legacy of one of the continent's longest-serving leaders.