Tens of thousands of Cubans lined up to pay their respects to Juan Almeida Bosque, a vice president and hero of the country's 1959 revolution whose death at the age of 82 further thinned the ranks of the communist-run country's old-guard leaders.
President Raul Castro led the ceremony at Havana's Revolution Square, somberly placing a pink rose in front of a large photograph of Almeida. Flags flew at half-mast throughout the country.
There was no sign of Castro's older brother, former leader Fidel Castro, who has not been seen in public since turning over power to his brother in 2006.
He released a statement later, writing: "I didn't know, neither did any of us, just how much pain news of his passing would bring.
"I was a privileged witness of his exemplary conduct during more than half a century of heroic and victorious resistance."
Raul Castro did not speak at the ceremony, but other Cubans filing past hailed Mr Almeida as a great and simple man.
"We have lost a party stalwart," said Manuel Perez, a 59-year-old labourer. "He was a man of great importance in the revolutionary fight."
Osmar Orozco, a 61-year-old pensioner, added that Mr Almeida's loyalty to Fidel Castro and the revolution was "without limit.
"That is why all Cubans could not fail to be here on this day," he said, wiping back tears.
Mr Almeida, one of just three surviving rebel leaders who still bore the title Commander of the Revolution, died on Friday of a heart attack.
Mr Almeida met Fidel Castro in 1952 at the University of Havana, where both were studying law, and he had been at Mr Castro's side ever since, through his imprisonment on the Isla de la Juventud, exile in Mexico and return to Cuba aboard the American yacht "Granma" in 1956 to launch the revolution.
Mr Almeida, the Castro brothers and Argentinian-born Ernesto "Che" Guevara were among only 16 rebels who survived the landing, in which most of the rebels were killed by government troops.
"No one here gives up!" Mr Almeida shouted to Guevara at the time, giving the Cuban revolution one of its most lasting slogans and ensuring his place in Cuban communist history. As a guerrilla leader, Mr Almeida later headed his own front of military operations in eastern Cuba.