Cuba's President Fidel Castro - the world's longest-serving leader - turns 80 on 13 August. This week, we are assessing his political life and his impact on the Caribbean island.
The Ladies in White are a group of political prisoners' wives
Here, the BBC's Elinor Shields asks whether Cuban dissidents can deliver on their hopes for change.
Cuban exiles in Miami may be celebrating in the streets at the news of Fidel Castro's temporary handover, but dissidents within the island have kept a lower profile.
"In Havana, people don't speak; they whisper," one wrote in a piece posted on CubaNet, one of the main external dissidence hubs in Florida.
"They take refuge in their silent ally of four decades: the wait."
The chance for a new era in Cuba may have finally arrived - but the island's small, split and scattered opposition faces many obstacles to their calls for change.
A small number of activists and journalists have fought for decades to end political imprisonments and restrictions on free speech under Mr Castro.
But public protests against the government are very rare in Cuba.
A few have taken prominent stands, such as democracy advocate Oswaldo Paya, who has gathered thousands of signatures for his petition for a referendum on whether Cubans favour such rights as freedom of speech, free elections, and the ability to own private businesses.
But most work in a more clandestine manner, on an island where dissidents face neighbourhood informants and state security agents - and open dissidence may bring harassment or jail.
"Fear is everywhere in Cuba," poet and journalist Raul Rivero told the BBC.
He was among the 75 dissidents handed long jail sentences in 2003 before he was released following international pressure, and went into exile in Spain.
"We now have a theatrical society whose script is written every day by the official press."
Observers say the 2003 crackdown dealt a heavy blow to human rights activists and the independent press.
Its "clandestine situation has forced" Cuba's press to function as one "from the inside for the outside", watchdog Reporters Without Borders says.
Analysts say dissidents must also rely on outside support to survive.
"You can't operate in Cuba without assistance from outside," Holly Ackerman, a scholar at Duke University, told the BBC.
Much of that assistance comes from Miami exile groups, who have received millions of dollars in US aid.
Oswaldo Paya is one of the few well-known dissidents
But some Cuban activists say American support hinders their cause.
Mr Paya told the Associated Press that Cubans on the island would reject any change seen to be imposed from outside, since the people in Cuba were the ones who needed political and economic reforms.
The opposition is also hampered by personal and political differences among some of the groups.
Dozens of small groups are believed to operate in Cuba - but they are often suspicious of one another because many of them have been infiltrated by government spies.
Prominent dissidents Martha Beatriz Roque and Mr Paya belong to rival factions and often feud, with Ms Roque opposing reconciliation among Cubans and Mr Paya seeking consensus and dialogue.
Some see this fragmentation as a factor in the dissidents' response to Mr Castro's temporary handover.
"If the movement was united... maybe this would be an opportunity," human rights advocate Laura Pollan told the Washington Post.
"But we have so much differences."
Exiles and the Bush administration have urged Cubans to push for change during Mr Castro's illness, but there has been little reaction on the island.
Many critics of Fidel Castro left Cuba for Florida
Some dissidents say they are fearful of retaliation in this period of uncertainty.
But others see it as a defining moment.
Mr Paya told the Associated Press that Mr Castro's illness had changed Cuba forever by exposing the system to the influence of others - even if only temporarily.
"This should be a moment of peace, serenity," he said earlier this week.
"The time has come for us to really put our heads together."