By Matt Frei
BBC News, Washington
Drama was the signature tune of Fidel's career.
Will Cuba's Communist Revolution outlive Fidel Castro's reign?
Towering well above 6ft (1.82m), chomping on a super-sized cigar and prone to marathon speeches, he was like a green fatigues-clad giant hailing from political folklore.
His opponents reviled him as an evil Gruffalo. I remember a diminutive Cuban granny in Havana waving her fist at me when I asked her what she thought about the ailing Mr Castro.
"Que se muera!" ("I hope he dies!") she rasped and stomped off in a huff, clutching a shopping bag half-empty from the meagre pickings of a Cuban ration store.
His supporters revered him as the David who stood up to Uncle Sam's Goliath.
It is too early to say whether Fidel will truly slip into the shadows of retirement and indeed live out his pension in peace
I remember Hugo Chavez, the Venezuelan president and Castro's understudy in baiting Washington, at a Non-Aligned Movement summit in Havana using language that even El Comandante would have deemed excessively florid.
"Fidel is the air we breathe, the grass we tread on, the tears in my eyes, the sweat on my face... Fidel is everywhere!" Chavez blubbered, over-egging an already stodgy pudding of adulation.
And yet it is hard not to resort to some hyperbole. Mr Castro ruled, or misruled, for almost half a century.
He was beaten in this record on the throne only by the current Queen of England, although she, of course, was never allowed to give five-hour speeches or lock up her opponents.
He survived countless assassination attempts, poisoned cigars and botched invasions.
Mr Castro, seen here with Che Guevara, took power in 1959
He helped to bring the world to the brink of nuclear war.
Almost alone he outlived the end of Communism and the sudden and brutal severance of economic aid from Moscow which starved his island into extreme poverty but never into submission.
He out-lasted nine American presidents and thumbed his nose at the mightiest military on the earth, which is moored just 90 miles (144km) off the Malecon, the crumbling seaside promenade in Havana where young Cubans look out over the horizon, plot their escape, dream of a different life or just chat.
In the end, Mr Castro even seems to have cheated death.
Last year, his opponents pointed to his plummeting weight and waited for him to die.
So after such a turbulent career, who would have imagined that his eventual exit from power would not involve hanging from a tree like Benito Mussolini, taking his own bullet or being executed by firing squad like Nicolae Ceausescu?
He was not deposed by the party, sacked by his politburo or felled prematurely by the Grim Reaper.
Mr Castro announced his retirement in the Communist Party newspaper
Fidel tells us he is retiring at the age of 81. He announced it in a letter in the Granma newspaper, the official organ he founded. It is a most unusual way for a despot to bow out.
It is too early to say whether Fidel will truly slip into the shadows of retirement and indeed live out his pension in peace.
His brother Raul is expected to take over. But Raul is hardly a spring chicken at the age of 76 and he is not exactly over-endowed with the charisma that can sustain incompetent regimes.
He has run the army for as long as Fidel has run the country, which means he has been able to nurture a crucial powerbase, but he has also done a lot of his brother's dirty work.
Most notably he presided over the arrest, trial and execution in 1989 of General Arnaldo Ochoa Sanchez, a decorated war hero who was accused of corruption and shipping drugs to the US - falsely, many believe.
I am told by friends in Cuba that this has built up a reservoir of resentment amongst the officer corps.
Uncle Sam's strategy
Then there is the economy. Raul is said to favour keeping the politics closed but opening the economy up for commerce.
But it is when regimes flirt with reform that their brittle house can collapse.
Brother Raul Castro is no spring chicken at 76 years old
However fabulous the Cuban health service may be, or the island's literacy rates, books and syringes do not feed people.
But they do make them healthy and clever enough to know what they are missing.
There is no underestimating the resentment bred by fear, poverty and incompetence.
And, of course, there is no shortage of Cuban relatives crowing over the water from Miami, their boats and yachts poised for a counter-revolutionary armada.
Ironically, the best hope that Raul has to stay in power lies in Washington.
The US Secretary of Commerce, Carlos Gutierrez, who left Cuba at the age of six, confirmed to me in an interview that the Bush administration will plough on with the economic embargo.
If so, Raul can probably continue to unite his island nation behind the ogre of Uncle Sam.
After half a century, how about a different approach? End the embargo, flood Cuba with Hershey bars, organise air-drops of dollars and kill the regime with kindness.
Matt Frei is the presenter of BBC World News America which airs every weekday at 0030 GMT on BBC News 24 and at 0000 GMT (1900 ET / 1600 PT) on BBC World and BBC America (for viewers outside the UK only).