Through the space age, the fall of the Berlin Wall and the internet era, Cubans held one constant: a Castro ruled the nation. But that is about to change.

Raul Castro, 86, is expected to step aside as Cuba’s president this week, ending the epochal run of two brothers who sent shock waves through 20th century politics. Nearly two decades into this century and less than two years after Fidel Castro’s death, his brother’s exit from Cuba’s top job leaves this insular island at a crossroads, weighing how fast, if at all, to embrace change.

“This is an important moment for Cuba, but the truth is, nobody knows what to expect,” says Camilo Condis, general manager of Artecorte, a community project in Havana. “I mean, other than Fidel and Raul, who is there? You didn’t really know anyone else.”

In a session of the National Assembly opening on Wednesday – and probably culminating with a succession vote on Thursday – members are expected to replace Castro with Miguel Diaz-Canel. Born after the revolution, Diaz-Canel, 57, grew up in the shadow of the olive-drab-wearing guerrillas who remain a powerful if ageing force in Cuba’s decision making apparatus. He is viewed as a consensus builder unlikely to push for quick or radical reform.

Castro has laid the groundwork for his exit for years and the passing of the torch is highly symbolic. When Raul took the reins from Fidel in 2008, a Castro was still in charge. This time, the succession amounts to a tricky effort to build a new generation of leaders without the Castro name, a move considered essential to cementing the central role of Cuba’s communist system.

“This is about institutionalising the regime,” said Jorge Domínguez, a Cuba expert and professor of government at Harvard University. “It’s about Raul Castro saying, ‘I am president, but I have a term and then someone else is going to lead ... If you are someone who really wants the regime to endure, it’s what Raul needs to do.”

The transition is happening at a time when a decade-long opening under Castro has already begun to alter the fabric of Cuban life. Access to the internet is still below par, but hotspots are more widely available than ever before. There are now more than 5 million mobile phones in this nation of 11.5 million people. More than 550,000 Cubans work in the private sector. After years in which Cubans were forced to obtain permission to leave the country, Cubans these days can travel freely. It is now possible to buy and sell real estate.

Yet in a country where streets are still swimming in 1950s Chevys and Fords, Cuban life can feel stuck in time and plagued with problems that never really went away. Locals talk of periodic shortages – eggs, potatoes and toilet paper. In a potential sign of discontent, turnout in recent municipal elections stood at 82.5 per cent – the lowest in four decades and a stunningly low number in a country where citizens face high pressure to vote.

Perhaps not surprisingly in a one-party state, few here are openly clamouring for radical political change. And in an important sense, this week’s transition will not mean the end of Castro leadership, since Castro will remain the head of the powerful Communist Party.

But some are testing the boundaries of official tolerance through independent minded blogs and social media. More and more Cubans are calling for a path to economic prosperity.

That desire for advancement is presenting Cuba’s ruling elite with a growing challenge: how and whether to more closely follow in the footsteps of communist societies like China and Vietnam, which have managed to ringfence their one-party systems while vastly expanding the private sector. Cuba’s economic opening has been far slower and has unfolded in fits and starts.

“We may find that the only way to preserve the achievements of the revolution is to change the country in substantial ways,” said Carlos Alzugaray, a former Cuban diplomat based in Havana.

Castro revolution lives on in the Cuban Sierra Maestra mountains Show all 15 1 /15 Castro revolution lives on in the Cuban Sierra Maestra mountains Castro revolution lives on in the Cuban Sierra Maestra mountains Mountains seen from La Plata, in the Sierra Maestra, Cuba REUTERS Castro revolution lives on in the Cuban Sierra Maestra mountains Workers take a break as they build a house at a farm in the village of Santo Domingo REUTERS Castro revolution lives on in the Cuban Sierra Maestra mountains Mechanic Dayan Nunes, 20, sits on a donkey in the village of La Merced REUTERS Castro revolution lives on in the Cuban Sierra Maestra mountains People watch the recording of an episode of the popular TV show ‘Palmas y Canas’ in the village of Providencia REUTERS Castro revolution lives on in the Cuban Sierra Maestra mountains Farmer Alexander Castillo, 37, talks to a friend at the doorstep of his home in the village of Santo Domingo REUTERS Castro revolution lives on in the Cuban Sierra Maestra mountains A horse stands in the mountains near the village of Santo Domingo REUTERS Castro revolution lives on in the Cuban Sierra Maestra mountains The village of Santo Domingo is seen in the Sierra Maestra REUTERS Castro revolution lives on in the Cuban Sierra Maestra mountains Bananas are being prepared for lunch in the kitchen of a house in the village of Santo Domingo REUTERS Castro revolution lives on in the Cuban Sierra Maestra mountains Farmer Luca Castillo, 84, poses for a photograph in front of his home in the village of Santo Domingo, in the Sierra Maestra REUTERS Castro revolution lives on in the Cuban Sierra Maestra mountains A chef sits in a food station during the recording of an episode of the popular TV show ‘Palmas y Canas’ in the village of Providencia REUTERS Castro revolution lives on in the Cuban Sierra Maestra mountains People attend the recording of an episode of the popular TV show ‘Palmas y Canas’ in the village of Providencia REUTERS Castro revolution lives on in the Cuban Sierra Maestra mountains Hipolito Marrero, 83, smokes a cigar as he commutes on horseback in the mountains near the village of Santo Domingo REUTERS Castro revolution lives on in the Cuban Sierra Maestra mountains Farmer Javier Tamayo, 55, rides his horse in the mountains near the village of Santo Domingo REUTERS Castro revolution lives on in the Cuban Sierra Maestra mountains Local official guide Luis Enrique Perez closes a window of the house where the late president Fidel Castro lived in the village of La Plata during the Cuban revolution REUTERS Castro revolution lives on in the Cuban Sierra Maestra mountains A boy raises the Cuban flag during a daily ceremony held at a school in the village of Santo Domingo, in the Sierra Maestra, Cuba Reuters

Cuba’s National Assembly will pick Castro’s successor, with Diaz-Canel seen by insiders as by far the most likely successor. An engineer often seen toting a tablet computer, he has been serving as Cuba’s first vice president.

Though he lacks the Castro name – the most senior member of government among the Castro brothers’ children is Raul Castro’s son, Colonel Alejandro Castro Espín, who heads counterintelligence – Diaz-Canel is without doubt blessed by Raul. He has been a constant presence at the side of his reform minded mentor. But he has also curried favour with the hardliners, who have largely succeeded in stalling a more drastic opening here.

Some Cubans hope that, given his relatively young age, Diaz-Canel may be willing to take economic reforms further than the Castros ever did. Yet he is also viewed as a party ideologue who was sceptical of the thaw with the United States under president Barack Obama and whose position on freedom of expression appears to have hardened in recent years. In a video leaked last year, for instance, Diaz-Canel is shown in a party meeting threatening to block a website for acting “against the revolution”.

“The people are committed to socialism and the historic generation that led us here,” Diaz-Canel told journalists last month.

Cuba watchers are waiting to see any shifts this week in the makeup of the nation’s ruling councils of ministers and state and are particularly keen to see whether senior figures in the revolution, now in their eighties, remain in place.

The transition is complicated by a seesaw in US-Cuba relations. The thaw under Obama has given way to a new frost under president Donald Trump. After allegations of a mysterious attack that left nearly two dozen US diplomats stationed in Cuba with brain injuries, Washington has left only a skeleton crew at its embassy in Havana.

The United States is now forcing Cubans looking for visas to apply in Guyana, nearly 2,000 miles away, putting the brakes on a host of personal trips and cultural exchanges.

The island’s nascent private sector, meanwhile, is under strain, because of actions by both the Cuban and US governments. Cuban officials last year put a temporary halt on issuing new licences for private businesses, arguing that time was needed to ensure that the island’s new crop of entrepreneurs were paying taxes and operating within the law. The freeze was seen as motivated by influential party officials still highly sceptical of change.

At the same time, Cuban officials say Trump administration policies have curtailed the flow of American tourists, who had begun to stream into the country in larger numbers under Obama.

Cubans like Julia de la Rosa and Silvio Ortega see themselves as caught in the middle of the two countries’ policies. In the first few months of 2017, Americans accounted for nearly 70 per cent of the visitors at the 10-room home that de la Rosa and Ortega rent out on Airbnb – a number that has fallen to about 10 per cent in recent months.

“You have to understand, when Obama came to Cuba [in 2016], people here thought he was like a movie star and that maybe the problem of relations would be solved,” De la Rosa said. “But now we find that’s not the case and we in the private sector are the ones paying.”

And yet, at least one line of communication is still flourishing: the one between Cubans on the island and Cuban exiles and their children in the United States.

In recent years, more and more Cuban islanders – including some who still at least partly embrace the revolution – have been travelling to cities like Miami, bringing a diversity of political opinion to US Cuban culture. Young Cuban Americans, meanwhile, continue to discover their roots through visits to the island, sparking a growing dialogue across the Straits of Florida.

Andrew Hevia, a 33-year-old half-Cuban Miamian and co-producer of the Academy Award-winning film Moonlight, for instance, is heading to Havana this month for the first time. His visit is being organised by CubaOne, a nonprofit that has brought more than 100 Cuban Americans to the island since 2016.

“My grandmother, who passed a number of years ago, would have been the one who had the most problems with me going,” he says.

But, he adds, “the conversation in Miami has changed about going to Cuba. Maybe it’s that there’s less resistance in my parents’ generation, or that [my generation is] taking the initiative, forcing things to come along.”