This work is a critical study of Mohammed Alioum Fantouré's Cerle des Tropiques. It focuses on the major themes of this masterpiece of French-speaking Black African literature, in particular the exercise of power in Black Africa. The first part of this study outlines the similarities between the fictional dictatorship and that actually experienced in the Republic of Guinea. It also highlights the main characteristics of Fantour's writing, demonstrating that Le Cercle des Tropiques is a novel with a political scope that gives an overall idea of the situation of a state on the eve of independence. The other two parts of the study analyze the salient features of the dictator in power and his single party. They focus in particular on the main allies of his policies: colonization, magico-religious practices and clan hierarchy.