Raul Castro is resigning as head of Cuba’s Communist Party, ending an era of leadership by him and his brother Fidel Castro that began with the 1959 revolution.
Mr Castro, 89, made the announcement on Friday in a speech at the opening of the Eighth congress of the ruling party.
"I believe fervently in the strength and exemplary nature and comprehension of my compatriots, and as long as I live I will be ready with my foot in the stirrups to defend the fatherland, the revolution and socialism," Mr Castro said at the Havana convention.
Mr Castro did not say who he would endorse as his successor as first secretary-general of the Communist Party, but he previously has indicated that he favours yielding control to Miguel Diaz-Canel, who succeeded him as president in 2018.
Some experts, however, think Mr Castro is unlikely to completely leave power behind and could continue to be operate as a puppet master.
Mr Diaz-Canel, a keen fan of The Beatles, is less likely to be seen in full military garb. He is seen as more modern, but is still a disciple of the Communist Party.
Cuba is currently suffering from a financial crisis and food shortages, leaving its political leaders with plenty of work to do if they are to turn the tide.
The country is trying to recover form the Covid-19 crisis, which has seen the tourism industry struggle due to a loss of foreign visitors.
Another issue that the leaders face comes from the youth in the country, who are calling for greater rights and freedom of speech.