Supporters have praised him for bringing social advances to Cuba, while critics have highlighted his government's repression and alleged human rights violations. Read more on Castro's life and legacy here
Throughout the Cold War, Fidel Castro was a thorn in Washington's side.
The CIA tried to assassinate him, most infamously with Operation Mongoose. Getting him to smoke a cigar packed with explosives was one idea.
Others were even more bizarre, including one to make his beard fall out and make him into a figure to be ridiculed.
In all, there were 638 assassination attempts, according to the Cuban secret service. But Castro managed to survive them all.
Here, Dr Stefan Halper, who served in the Nixon, Ford and Reagan administrations, tells the BBC how the US tried - and failed - to unseat him.
How Castro's death played on social media
Fidel Castro's death drew a fierce reaction online from those who loved and loathed him.
It is hard, however, to get a sense of what users living in Cuba think, as internet use is extremely restricted there.
But Havana-based journalist Yoani Sanchez managed to share a local perspective. Writing in Spanish, she said ordinary Cubans were showing "indifference" to Castro's death.
"Some are fired with pain, others with relief... the vast majority with a touch of indifference," Ms Sanchez tweeted.
Adding her own view, she said Castro's legacy was "a country in ruin, a nation where young people do not want [to] live".
But Castro was a polarising figure not only in Cuba, and users around the world took to Twitter to share their views.
Florida, where many Cubans fled after the Cuban Revolution, is a hotbed of anti-Castro sentiment.
There were celebrations in Miami following the news of Fidel Castro's death. People honked their car horns and set off fireworks. There were also shouts of "Cuba si! Castro no!'' and "Libertad!" (Freedom).
Harsh words came from Florida Republican Senator Marco Rubio, a Cuban-American. He said Fidel Castro turned Cuba "into an impoverished island prison".
He described the former Cuban leader as an "evil, murderous dictator.
The speaker of the House of Representatives Paul Ryan, also a Republican, said: "Now that Fidel Castro is dead, the cruelty and oppression of his regime should die with him."
"Today let us reflect on the memory and sacrifices of all those who have suffered under the Castros."
What next for US-Cuba relations?
GettyCopyright: Getty
Donald Trump's election as US president has put a question mark on Barack Obama's push to restore relations with the country, including plans to lift a decades-long embargo on the island, announced in 2014.
Mr Obama visited Havana earlier this year in a visit that marked a new chapter in US-Cuba relations. Embassies opened in Havana and Washington DC, and some business deals have already been announced.
But many are now wondering if the newly opened ties will hold.
The trade embargo can only be lifted by the US Congress, and Republicans, who will control both the Senate and the House of Representatives, have expressed their opposition to its removal.
And Mr Trump had promised anti-Castro Republicans that he would roll back on Mr Obama's detente, would keep the embargo on the island firmly in place and would even close the recently reopened US embassy in Havana.
However, it is still unclear if this was just campaign rhetoric.
In a statement after Fidel Castro's death, Mr Trump said: "Our administration will do all it can to ensure the Cuban people can finally begin their journey toward prosperity and liberty."
Mr Obama called his government's steps towards Cuba "irreversible". But many are based on executive orders and, when president, Mr Trump could repeal them.
Cuban state media opt for uplifting message
State-run newspaper Granma does not mention the death of Fidel Castro in its headline. It simply shows the revolutionary slogan "Onwards to victory, always" and a picture of Fidel Castro waving a Cuban flag.
GranmaCopyright: Granma
Obama: 'We worked hard to put the past behind us'
President Barack Obama's government will certainly be remembered as a game-changer on US-Cuba relations.
In 2014, he announced that the two countries would restore diplomatic relations after a decades-long break-up and a trade embargo imposed by the US.
The embargo, however, can only be lifted by the US Congress, and Republicans have expressed opposition to the plan.
Earlier this year, he made history as the first sitting US president to visit the island since the 1959 revolution. He visited the president Raul but not his brother, Fidel.
Here's Barack Obama's full statement on Castro's death.
White HouseCopyright: White House
BreakingTrump: 'Castro's legacy is one of firing squads, unimaginable suffering'
US President-elect Donald Trump has released a statement reacting to Fidel Castro's death:
"Today, the world marks the passing of a brutal dictator who oppressed his own people for nearly six decades. Fidel Castro's legacy is one of firing squads, theft, unimaginable suffering, poverty and the denial of fundamental human rights.
"While Cuba remains a totalitarian island, it is my hope that today marks a move away from the horrors endured for too long, and toward a future in which the wonderful Cuban people finally live in the freedom they so richly deserve.
"Though the tragedies, deaths and pain caused by Fidel Castro cannot be erased, our administration will do all it can to ensure the Cuban people can finally begin their journey toward prosperity and liberty. I join the many Cuban Americans who supported me so greatly in the presidential campaign, including the Brigade 2506 Veterans Association that endorsed me, with the hope of one day soon seeing a free Cuba."
Earlier, in a Tweet, Mr Trump had said: "Fidel Castro is dead!"
Justin Trudeau: Castro was 'a larger than life leader'
Canadian Prime Minister Justin Trudeau was in Cuba earlier this month, but a meeting between him and Fidel Castro did not happen.
The friendship between the former Cuban leader and the Trudeau family was decades-old.
Castro was an honorary pallbearer at the 2000 funeral of Justin's father, Pierre, who also served as PM of Canada.
Reacting to Castro's death, Justin Trudeau said he received the news with "great sadness".
He called Fidel Castro "a longtime friend of Canada and my family".
BreakingObama: 'History will record and judge Castro's impact'
US President Barack Obama offered his condolences to Fidel Castro's family in a statement.
"We know that this moment fills Cubans - in Cuba and in the United States - with powerful emotions, recalling the countless ways in which Fidel Castro altered the course of individual lives, families, and of the Cuban nation," he said.
"History will record and judge the enormous impact of this singular figure on the people and world around him."
Castro’s human rights legacy: 'Repression and persecution'
AFPCopyright: AFP
Allegations of human rights abuses have always been a thorn in the side of the Cuban government.
Observers say that despite being a charismatic leader responsible for many social advances on the island, Fidel Castro exerted a tough control over the country, with protests banned and those who defied the ban facing arrest.
The media is still tightly controlled by the government and journalists have to operate within the confines of laws against anti-government propaganda and the insulting of officials which carry penalties of up to three years in prison.
Reporters without Borders in early 2016 described Cuba as "one of the world's worst countries from the viewpoint of journalists… independent journalists and bloggers are constantly persecuted by the Castro government".
Orlando Guiterrez, from the Cuban Democratic Directorate, said Fidel Castro had set up a "vicious totalitarian regime" where people were persecuted for the slightest deviation from the official line.
For human rights group Amnesty International, "Fidel Castro’s achievements in improving access to public services for millions of Cubans were tempered by a systemic repression of basic freedoms during his time in power".
“The state of freedom of expression in Cuba, where activists continue to face arrest and harassment for speaking out against the government, is Fidel Castro’s darkest legacy,” Erika Guevara-Rosas, the group's Americas director, added.
Never lost for words
BBC Mundo
Fidel Castro was famous for many things, among them for making exceedingly long speeches. His longest lasted seven hours and 10 minutes, during the 1986 Communist Party Congress in Havana.
He also holds the record for the longest speech ever given at a UN General Assembly.
That clocked in at four hours and 29 minutes.
He told his biographer Ignacio Ramonet that he never gave a speech that hadn't been written by himself.
Speaking of numbers, during his days as a leader, Castro used to sleep only four hours a day, according to his biographer. Once in a while, he would catch an extra hour or two of sleep during the day.
He used to work seven days a week, usually going to bed early in the morning, at around 5:00.
Also legendary are pictures of Fidel Castro smoking. He said he took his first puff at the age of 14, accepting an offer from his father to give it a try.
He said he smoked a lot in his life before quitting in 1985.
Ladies in White: 'May God forgive him, I won't'
The Cuban dissident group Ladies in White has reacted to the death of Fidel Castro. In a tweet, the group said it would not forgive the late leader: Fidel Castro has died, may God forgive him, I WON'T"
The group, founded by wives of jailed dissidents, hold frequent protests in Havana.
Their members are regularly arrested. Cuban authorities say they are in the pay of the United States and form part of Washington's "decades-old effort to undermine Cuba's socialist revolution".
'Like an older brother', says Brazil's ex-leader Lula
Brazil's former President Luiz Inacio Lula da Silva said he felt the death of Fidel Castro "like the death of an older brother, an irreplaceable comrade whom I will never forget".
Lula of the Workers' Party came to office in 2003 as the first leftist leader in Brazil in nearly half a century.
He said that "in the worst moments, when dictatorships dominated the main nations in our region, Fidel Castro's bravery and the example set by the Cuban revolution inspired those who resisted to oppression".
Fidel Castro v US presidents
During Fidel Castro's time in power, 10 different US presidents occupied the White House.
Fidel Castro defied all of their efforts to topple him and continued to influence Cuban policy even after he handed over the reins of power to his brother, Raul.
And earlier this year, Barack Obama became the first US president to step foot on Cuban soil since 1928 - but the two did not meet.
BBCCopyright: BBC
Communist paper: 'Not a goodbye, but a farewell'
BBC Monitoring
News from around the globe
Newspapers around the world are leading with the death of the Cuban revolutionary leader.
Not surprisingly, Communist papers in Cuba are full of praise for Fidel Castro. The youth newspaper Juventud Rebelde invoked the lyrics of the Cuban revolutionary anthem Hasta Siempre in its tributes: "This is not a goodbye, but a farewell".
The rest of Cuba's tightly-controlled media took a similar line.
But many Western dailies are far more critical of the late leader. Spain's ABC, for example, calls him "a cheating tyrant". And Italy's Corriere della Sera details the history of Cuba under Castro with the headline "from utopia to torture".
Pope Francis said the death of Fidel Castro was "sad news", and that he was grieving and praying for his repose.
In a message in Spanish to Cuba's President Raul Castro, the Pope said: "I express to you my sentiments of grief."
The Pope met Fidel Castro during a visit to Cuba in September 2015.
Fidel Castro was a self-professed atheist but as a child he attended Catholic schools in Santiago before going on to the Jesuit-run El Colegio de Belen in Havana.
Cubans react to the death of Cuba's revolutionary leader Fidel Castro.
Farc rebel leader Timochenko: 'Eternal glory to Fidel!'
The leader of Colombia's largest rebel group, the Revolutionary Armed Forces of Colombia (Farc), said the memory of Fidel Castro deserved "eternal glory".
Rodrigo Londono, better known as Timochenko, said Castro was "one of the greatest" in the world.
The Farc rebels took much of their inspiration from the Cuban revolution.
More recently, Cuba played a key role in peace talks in Havana which led to the signing of a peace agreement earlier this week between the Farc and the Colombian government.
Live Reporting
Hugo Bachega, Vanessa Buschschluter and Heather Sharp
All times stated are UK
- You can find the latest on the reaction in Cuba and around the world here
- Supporters have praised him for bringing social advances to Cuba, while critics have highlighted his government's repression and alleged human rights violations. Read more on Castro's life and legacy here
- We take a look at Castro's image as a revolutionary that went well beyond Cuba's borders
- Here is a selection of some of Castro's most remarkable moments in pictures
TwitterCopyright: Twitter TwitterCopyright: Twitter GettyCopyright: Getty GranmaCopyright: Granma White HouseCopyright: White House AFPCopyright: AFP View more on twitterView more on twitter BBCCopyright: BBC APCopyright: AP
Latest PostEnd of our coverage
We are wrapping up our live coverage following the death of former Cuban President Fidel Castro.
How the US tried to get rid of Fidel Castro
Throughout the Cold War, Fidel Castro was a thorn in Washington's side.
The CIA tried to assassinate him, most infamously with Operation Mongoose. Getting him to smoke a cigar packed with explosives was one idea.
Others were even more bizarre, including one to make his beard fall out and make him into a figure to be ridiculed.
In all, there were 638 assassination attempts, according to the Cuban secret service. But Castro managed to survive them all.
Here, Dr Stefan Halper, who served in the Nixon, Ford and Reagan administrations, tells the BBC how the US tried - and failed - to unseat him.
How Castro's death played on social media
Fidel Castro's death drew a fierce reaction online from those who loved and loathed him.
It is hard, however, to get a sense of what users living in Cuba think, as internet use is extremely restricted there.
But Havana-based journalist Yoani Sanchez managed to share a local perspective. Writing in Spanish, she said ordinary Cubans were showing "indifference" to Castro's death.
"Some are fired with pain, others with relief... the vast majority with a touch of indifference," Ms Sanchez tweeted.
Adding her own view, she said Castro's legacy was "a country in ruin, a nation where young people do not want [to] live".
But Castro was a polarising figure not only in Cuba, and users around the world took to Twitter to share their views.
Read more on how users reacted here.
The view from Florida
Florida, where many Cubans fled after the Cuban Revolution, is a hotbed of anti-Castro sentiment.
There were celebrations in Miami following the news of Fidel Castro's death. People honked their car horns and set off fireworks. There were also shouts of "Cuba si! Castro no!'' and "Libertad!" (Freedom).
Harsh words came from Florida Republican Senator Marco Rubio, a Cuban-American. He said Fidel Castro turned Cuba "into an impoverished island prison".
He described the former Cuban leader as an "evil, murderous dictator.
The speaker of the House of Representatives Paul Ryan, also a Republican, said: "Now that Fidel Castro is dead, the cruelty and oppression of his regime should die with him."
"Today let us reflect on the memory and sacrifices of all those who have suffered under the Castros."
What next for US-Cuba relations?
Donald Trump's election as US president has put a question mark on Barack Obama's push to restore relations with the country, including plans to lift a decades-long embargo on the island, announced in 2014.
Mr Obama visited Havana earlier this year in a visit that marked a new chapter in US-Cuba relations. Embassies opened in Havana and Washington DC, and some business deals have already been announced.
But many are now wondering if the newly opened ties will hold.
The trade embargo can only be lifted by the US Congress, and Republicans, who will control both the Senate and the House of Representatives, have expressed their opposition to its removal.
And Mr Trump had promised anti-Castro Republicans that he would roll back on Mr Obama's detente, would keep the embargo on the island firmly in place and would even close the recently reopened US embassy in Havana.
However, it is still unclear if this was just campaign rhetoric.
In a statement after Fidel Castro's death, Mr Trump said: "Our administration will do all it can to ensure the Cuban people can finally begin their journey toward prosperity and liberty."
Mr Obama called his government's steps towards Cuba "irreversible". But many are based on executive orders and, when president, Mr Trump could repeal them.
Cuban state media opt for uplifting message
State-run newspaper Granma does not mention the death of Fidel Castro in its headline. It simply shows the revolutionary slogan "Onwards to victory, always" and a picture of Fidel Castro waving a Cuban flag.
Obama: 'We worked hard to put the past behind us'
President Barack Obama's government will certainly be remembered as a game-changer on US-Cuba relations.
In 2014, he announced that the two countries would restore diplomatic relations after a decades-long break-up and a trade embargo imposed by the US.
The embargo, however, can only be lifted by the US Congress, and Republicans have expressed opposition to the plan.
Earlier this year, he made history as the first sitting US president to visit the island since the 1959 revolution. He visited the president Raul but not his brother, Fidel.
Here's Barack Obama's full statement on Castro's death.
BreakingTrump: 'Castro's legacy is one of firing squads, unimaginable suffering'
US President-elect Donald Trump has released a statement reacting to Fidel Castro's death:
"Today, the world marks the passing of a brutal dictator who oppressed his own people for nearly six decades. Fidel Castro's legacy is one of firing squads, theft, unimaginable suffering, poverty and the denial of fundamental human rights.
"While Cuba remains a totalitarian island, it is my hope that today marks a move away from the horrors endured for too long, and toward a future in which the wonderful Cuban people finally live in the freedom they so richly deserve.
"Though the tragedies, deaths and pain caused by Fidel Castro cannot be erased, our administration will do all it can to ensure the Cuban people can finally begin their journey toward prosperity and liberty. I join the many Cuban Americans who supported me so greatly in the presidential campaign, including the Brigade 2506 Veterans Association that endorsed me, with the hope of one day soon seeing a free Cuba."
Earlier, in a Tweet, Mr Trump had said: "Fidel Castro is dead!"
Justin Trudeau: Castro was 'a larger than life leader'
Canadian Prime Minister Justin Trudeau was in Cuba earlier this month, but a meeting between him and Fidel Castro did not happen.
The friendship between the former Cuban leader and the Trudeau family was decades-old.
Castro was an honorary pallbearer at the 2000 funeral of Justin's father, Pierre, who also served as PM of Canada.
Reacting to Castro's death, Justin Trudeau said he received the news with "great sadness".
He called Fidel Castro "a longtime friend of Canada and my family".
BreakingObama: 'History will record and judge Castro's impact'
US President Barack Obama offered his condolences to Fidel Castro's family in a statement.
"We know that this moment fills Cubans - in Cuba and in the United States - with powerful emotions, recalling the countless ways in which Fidel Castro altered the course of individual lives, families, and of the Cuban nation," he said.
"History will record and judge the enormous impact of this singular figure on the people and world around him."
Castro’s human rights legacy: 'Repression and persecution'
Allegations of human rights abuses have always been a thorn in the side of the Cuban government.
Observers say that despite being a charismatic leader responsible for many social advances on the island, Fidel Castro exerted a tough control over the country, with protests banned and those who defied the ban facing arrest.
The media is still tightly controlled by the government and journalists have to operate within the confines of laws against anti-government propaganda and the insulting of officials which carry penalties of up to three years in prison.
Reporters without Borders in early 2016 described Cuba as "one of the world's worst countries from the viewpoint of journalists… independent journalists and bloggers are constantly persecuted by the Castro government".
Orlando Guiterrez, from the Cuban Democratic Directorate, said Fidel Castro had set up a "vicious totalitarian regime" where people were persecuted for the slightest deviation from the official line.
For human rights group Amnesty International, "Fidel Castro’s achievements in improving access to public services for millions of Cubans were tempered by a systemic repression of basic freedoms during his time in power".
“The state of freedom of expression in Cuba, where activists continue to face arrest and harassment for speaking out against the government, is Fidel Castro’s darkest legacy,” Erika Guevara-Rosas, the group's Americas director, added.
Never lost for words
BBC Mundo
Fidel Castro was famous for many things, among them for making exceedingly long speeches. His longest lasted seven hours and 10 minutes, during the 1986 Communist Party Congress in Havana.
He also holds the record for the longest speech ever given at a UN General Assembly.
That clocked in at four hours and 29 minutes.
He told his biographer Ignacio Ramonet that he never gave a speech that hadn't been written by himself.
Speaking of numbers, during his days as a leader, Castro used to sleep only four hours a day, according to his biographer. Once in a while, he would catch an extra hour or two of sleep during the day.
He used to work seven days a week, usually going to bed early in the morning, at around 5:00.
Also legendary are pictures of Fidel Castro smoking. He said he took his first puff at the age of 14, accepting an offer from his father to give it a try.
He said he smoked a lot in his life before quitting in 1985.
Ladies in White: 'May God forgive him, I won't'
The Cuban dissident group Ladies in White has reacted to the death of Fidel Castro. In a tweet, the group said it would not forgive the late leader: Fidel Castro has died, may God forgive him, I WON'T"
The group, founded by wives of jailed dissidents, hold frequent protests in Havana.
Their members are regularly arrested. Cuban authorities say they are in the pay of the United States and form part of Washington's "decades-old effort to undermine Cuba's socialist revolution".
'Like an older brother', says Brazil's ex-leader Lula
Brazil's former President Luiz Inacio Lula da Silva said he felt the death of Fidel Castro "like the death of an older brother, an irreplaceable comrade whom I will never forget".
Lula of the Workers' Party came to office in 2003 as the first leftist leader in Brazil in nearly half a century.
He said that "in the worst moments, when dictatorships dominated the main nations in our region, Fidel Castro's bravery and the example set by the Cuban revolution inspired those who resisted to oppression".
Fidel Castro v US presidents
During Fidel Castro's time in power, 10 different US presidents occupied the White House.
Fidel Castro defied all of their efforts to topple him and continued to influence Cuban policy even after he handed over the reins of power to his brother, Raul.
And earlier this year, Barack Obama became the first US president to step foot on Cuban soil since 1928 - but the two did not meet.
Communist paper: 'Not a goodbye, but a farewell'
BBC Monitoring
News from around the globe
Newspapers around the world are leading with the death of the Cuban revolutionary leader.
Not surprisingly, Communist papers in Cuba are full of praise for Fidel Castro. The youth newspaper Juventud Rebelde invoked the lyrics of the Cuban revolutionary anthem Hasta Siempre in its tributes: "This is not a goodbye, but a farewell".
The rest of Cuba's tightly-controlled media took a similar line.
But many Western dailies are far more critical of the late leader. Spain's ABC, for example, calls him "a cheating tyrant". And Italy's Corriere della Sera details the history of Cuba under Castro with the headline "from utopia to torture".
Read more about media reaction from around the world.
Pope: Castro's death 'sad news'
Pope Francis said the death of Fidel Castro was "sad news", and that he was grieving and praying for his repose.
In a message in Spanish to Cuba's President Raul Castro, the Pope said: "I express to you my sentiments of grief."
The Pope met Fidel Castro during a visit to Cuba in September 2015.
Fidel Castro was a self-professed atheist but as a child he attended Catholic schools in Santiago before going on to the Jesuit-run El Colegio de Belen in Havana.
You can read more on his life here.
'He will always be our commander'
Cubans react to the death of Cuba's revolutionary leader Fidel Castro.
Farc rebel leader Timochenko: 'Eternal glory to Fidel!'
The leader of Colombia's largest rebel group, the Revolutionary Armed Forces of Colombia (Farc), said the memory of Fidel Castro deserved "eternal glory".
Rodrigo Londono, better known as Timochenko, said Castro was "one of the greatest" in the world.
The Farc rebels took much of their inspiration from the Cuban revolution.
More recently, Cuba played a key role in peace talks in Havana which led to the signing of a peace agreement earlier this week between the Farc and the Colombian government.
'First free elections in 18 months'
A week after Batista was overthrown, Fidel Castro said the first free election would probably be in 18 months' time.