The new president of Cuba has been confirmed as Miguel Diaz-Canel, ending nearly six decades at the helm for the Castro family.
Raul Castro's departure from the role launches a new political era for a country trying to survive as one of the world's last communist states.
The new head of state, full name Miguel Mario Diaz-Canel Bermudez, had been approved as the sole candidate for president.
The 86-year-old Mr Castro, brother of late former leader Fidel, will remain head of the Communist Party.
Members of the National Assembly opened the crucial session a day after voting on Mr Diaz-Canel's nomination.
Mr Castro's departure from the presidency is nonetheless a symbolically charged moment for a country that has been under the absolute rule of one family since the revolution.
Revolutionary leader Fidel Castro ruled the nation before, for the last decade, his younger brother filled his shoes.
Facing biological reality but still active and apparently healthy, Mr Castro is stepping down as president in an effort to guarantee that new leaders can maintain the government's grip on power in the face of economic stagnation, an ageing population and increasing disenchantment among younger generations.
"I like sticking with the ideas of President Fidel Castro because he did a lot for the people of Cuba, but we need rejuvenation, above all in the economy," said Melissa Mederos, a 21-year-old schoolteacher.
"Diaz-Canel needs to work hard on the economy, because people need to live a little better."
Most Cubans know their first vice president as an uncharismatic figure who until recently maintained a public profile so low it was virtually non-existent.
That image changed slightly this year as state media placed an increasing spotlight on Mr Diaz-Canel's public appearances, including remarks to the press last month that included his promise to make Cuba's government more responsive to its people.
"We're building a relationship between the government and the people here," he said then after casting a ballot for members of the National Assembly.
"The lives of those who will be elected have to be focused on relating to the people, listening to the people, investigating their problems and encouraging debate."
Mr Diaz-Canel gained prominence in central Villa Clara province as the top Communist Party official, a post equivalent to governor.
People there describe him as a hard-working, modest-living technocrat dedicated to improving public services.
He became higher education minister in 2009 before moving into the vice presidency.
In a video of a Communist Party meeting that inexplicably leaked to the public last year, Mr Diaz-Canel expressed a series of orthodox positions that included sombrely pledging to shutter some independent media and labelling some European embassies as outposts of foreign subversion.
But he has also defended academics and bloggers who became targets of hardliners, leading some to describe him a potential advocate for greater openness in a system intolerant of virtually any criticism or dissent.
International observers and Cubans alike will be scrutinising every move he makes after he officially takes office today.