Almeida (top right) was among the victorious revolutionaries in 1959
One of the original protagonists of the Cuban revolution, Juan Almeida Bosque, has died of heart failure at the age of 82, according to state media.
Almeida was one of several vice-presidents in the Council of State under Raul Castro.
He was the only black commander in the Cuban leadership.
From a poor Havana neighbourhood, Almeida was in the group of guerrillas led by Fidel Castro which eventually seized power in Cuba in 1959.
He went on to become a general in the armed forces, a member of the politburo of the Communist Party and the third-ranking member in the Council of State.
State-run media announced his death, declaring he would remain "in the hearts and minds of his compatriots".
Sunday has been declared a national day of mourning, and flags will be flown at half-mast.
There will be no lying-in-state, in accordance with Almeida's wishes. He will be given a military funeral at a later date.
A former construction worker, Almeida participated in the failed 1953 assault on the Moncada military barracks in Santiago de Cuba, and was among those sent to jail.
Almeida could often be seen at the side of Fidel and Raul Castro
Following an amnesty, the rebels were released and in 1956 they went to Mexico to regroup and prepare for a fresh assault.
Almeida was on board the Granma boat when it sailed back to Cuba carrying the small group of fighters that would launch the insurrectionary campaign from the Sierra Maestra mountains.
He was promoted to the rank of commander during the mountain campaign.
Outnumbered in one of the early battles, Juan Almeida is said to have stormed to the front shouting, "Here, nobody surrenders!"
It became a slogan of the revolution.