The Cuban Revolution was not the work of one man, nor was it the result of one key event. To understand the revolution, you must understand the men and women who fought it, and you must understand the battlefields - physical as well as ideological - where the Revolution was won.
While it's true that the revolution was the result of years of effort by many people, it is also true that without the singular charisma, vision and willpower of Fidel Castro it probably would not have happened. Many around the world love him for his ability to thumb his nose at the mighty United States (and get away with it) while others despise him for turning the booming Cuba of the Batista years into an impoverished shadow of its former self. Love him or hate him, you must give Castro his due as one of the most remarkable men of the last century.
No story is any good without a good villain, right? Batista was President of Cuba for a time in the 1940's before returning to power in a military coup in 1952. Under Batista, Cuba prospered, becoming a haven for wealthy tourists looking to have a good time in the fancy hotels and casinos of Havana. The tourism boom brought with it great wealth... for Batista and his cronies. Poor Cubans were more miserable than ever, and their hatred of Batista was the fuel that drove the revolution. Even after the revolution, upper and middle-class Cubans who lost everything in the conversion to communism could agree on two things: they hated Castro, but didn't necessarily want Batista back.
It's easy to forget about Raul Castro, Fidel's little brother who started tagging along behind him when they were kids...and seemingly never stopped. Raul faithfully followed Fidel to the assault on the Moncada barracks, into prison, into Mexico, back to Cuba on board a leaky yacht, into the mountains and into power. Even today, he continues to be his brother's right-hand man, serving as President of Cuba when Fidel became too sick to continue. He should not be overlooked, as he himself played important roles in all of the stages of his brother's Cuba, and more than one historian believes that Fidel would not be where he is today without Raul.
In July of 1953, Fidel and Raul led 140 rebels in an armed assault on the federal army barracks at Moncada, outside of Santiago. The barracks contained arms and munitions, and the Castros hoped to acquire them and kick off a revolution. The assault was a fiasco, however, and most of the rebels wound up dead or, like Fidel and Raul, in prison. In the long run, however, the brazen assault cemented Fidel Castro's place as leader of the anti-Batista movement and as discontent with the dictator grew, Fidel's star rose.
Exiled in Mexico, Fidel and Raul began recruiting for another attempt at driving Batista out of power. In Mexico City, they met the young Ernesto "Che" Guevara, an idealistic Argentine doctor who had been itching to strike a blow against imperialism since he had witnessed first-hand the CIA's ouster of President Arbenz in Guatemala. He joined the cause and would eventually become one of the most important players in the revolution. After serving some years in the Cuban government, he went abroad to stir up communist revolutions in other nations. He did not fare as well as he had in Cuba and was executed by Bolivian security forces in 1967.
Also while in Mexico, the Castros picked up a young, wiry kid who had gone into exile after being involved in anti-Batista protests. Camilo Cienfuegos also wanted in on the revolution, and he would eventually be one of the most important players. He traveled back to Cuba on board the legendary Granma yacht, and became one of Fidel's most trusted men in the mountains. His leadership and charisma were evident, and he was given a large rebel force to command. He fought in several key battles and distinguished himself as a leader. He died in a plane accident shortly after the revolution.