Since The rebel Army of about 9000 strong under the supreme command of Fidel Castro entered Havana in 1959 after the departure of Fulgienco Batista a picture of gradual but steady concentration of power in the hands of the revolutionaries has taken place in Cuba.
The original triumvirate consisting of Fidel Castro, Prime Minister, his brother Raul as a deputy and Che Guevara, the third in command, set in motion a series of revolutionary and nationalistic policies which increased its popularity in the masses and place it in a course of unavoidable confrontation with the traditional domineering forces of the country and the US interests in the Island.
The traditional domineering forces were shaped throughout Cuba history by the logistics of Spanish colonization and the production goods by the island. During the time of colonization, the landowners became gradually the latifundios which had huge plantations of sugar and thousand of African slaves. After the emancipation of the slaves, this structure remained as central organizational schematic of the Cuban economy. As it happen, in all the colonies in the Americas, the conflict of interest between the land owners and the colonial power created an embryonic nationalistic movement. This nationalistic movement gave the national identity of Cuba its primary anti colonialist and anti imperialist nucleus which will be used with tremendous success by Fidel Castro against his political enemies and against the United States.
The Fundamental instrument of political power in Cuba is the Cuban Communist party which is the only recognized political party in Cuba. It is headed by Fidel Castro who is assisted by a directorate.
In 1976 Cuba published the socialist constitution which proclaimed the adhesion of the country to the Marxist Leninist ideology and international proletarian's power movement. This constitution was modified later but the fundamental law governing the country remained the same and Fidel Castro remains in power.