Castro formed a group called "The Movement" which operated along a clandestine cell system, publishing underground newspaper El Acusador (The Accuser), while arming and training anti-Batista recruits.
From July 1952 they went on a recruitment drive, gaining around 1,200 members in a year, the majority from Havana's poorer districts.
Although a revolutionary socialist, Castro avoided an alliance with the communist Popular Socialist Party (PSP), fearing it would frighten away political moderates, but kept in contact with PSP members like his brother Raúl.
Castro stockpiled weapons for a planned attack on the Moncada Barracks, a military garrison outside Santiago de Cuba, Oriente.
Castro's militants intended to dress in army uniforms and arrive at the base on 25 July, seizing control and raiding the armory before reinforcements arrived.
Supplied with new weaponry, Castro intended to spark a revolution among Oriente's impoverished cane cutters and promote further uprisings.
Castro's plan emulated those of the 19th-century Cuban independence fighters who had raided Spanish barracks; Castro saw himself as the heir to independence leader José Martí.

Castro gathered 165 revolutionaries for the mission, ordering his troops not to cause bloodshed unless they met armed resistance.
The attack took place on 26 July 1953, but ran into trouble; 3 of the 16 cars that had set out from Santiago failed to get there.
Reaching the barracks, the alarm was raised, with most of the rebels pinned down by machine gun fire.
Four were killed before Castro ordered a retreat.
The rebels suffered 6 fatalities and 15 other casualties, whilst the army suffered 19 dead and 27 wounded.
Meanwhile, some rebels took over a civilian hospital; subsequently stormed by government soldiers, the rebels were rounded up, tortured and 22 were executed without trial.
Accompanied by 19 comrades, Castro set out for Gran Piedra in the rugged Sierra Maestra mountains several kilometres to the north, where they could establish a guerrilla base.
Responding to the attack, Batista's government proclaimed martial law, ordering a violent crackdown on dissent, and imposing strict media censorship.
The government broadcast misinformation about the event, claiming that the rebels were communists who had killed hospital patients, although news and photographs of the army's use of torture and summary executions in Oriente soon spread, causing widespread public and some governmental disapproval.

Over the following days, the rebels were rounded up; some were executed and others – including Castro – transported to a prison north of Santiago.
Believing Castro incapable of planning the attack alone, the government accused Ortodoxo and PSP politicians of involvement, putting 122 defendants on trial on 21 September at the Palace of Justice, Santiago.
Acting as his own defense counsel, Castro cited Martí as the intellectual author of the attack and convinced the three judges to overrule the army's decision to keep all defendants handcuffed in court, proceeding to argue that the charge with which they were accused – of "organizing an uprising of armed persons against the Constitutional Powers of the State" – was incorrect, for they had risen up against Batista, who had seized power in an unconstitutional manner.
The trial embarrassed the army by revealing that they had tortured suspects, after which they tried unsuccessfully to prevent Castro from testifying any further, claiming he was too ill.
The trial ended on 5 October, with the acquittal of most defendants; 55 were sentenced to prison terms of between 7 months and 13 years.
Castro was sentenced on 16 October, during which he delivered a speech that would be printed under the title of History Will Absolve Me.
Castro was sentenced to 15 years' imprisonment in the hospital wing of the Model Prison (Presidio Modelo), a relatively comfortable and modern institution on the Isla de Pinos.
Castro formed a group called "The Movement" which operated along a clandestine cell system, publishing underground newspaper El Acusador (The Accuser), while arming and training anti-Batista recruits. From July 1952 they went on a recruitment drive, gaining around 1,200 members in a year, the majority from Havana's poorer districts. Although a revolutionary socialist, Castro avoided an alliance with the communist Popular Socialist Party (PSP), fearing it would frighten away political moderates, but kept in contact with PSP members like his brother Raúl. Castro stockpiled weapons for a planned attack on the Moncada Barracks, a military garrison outside Santiago de Cuba, Oriente. Castro's militants intended to dress in army uniforms and arrive at the base on 25 July, seizing control and raiding the armory before reinforcements arrived. Supplied with new weaponry, Castro intended to spark a revolution among Oriente's impoverished cane cutters and promote further uprisings. Castro's plan emulated those of the 19th-century Cuban independence fighters who had raided Spanish barracks; Castro saw himself as the heir to independence leader José Martí.
Castro gathered 165 revolutionaries for the mission, ordering his troops not to cause bloodshed unless they met armed resistance. The attack took place on 26 July 1953, but ran into trouble; 3 of the 16 cars that had set out from Santiago failed to get there. Reaching the barracks, the alarm was raised, with most of the rebels pinned down by machine gun fire. Four were killed before Castro ordered a retreat. The rebels suffered 6 fatalities and 15 other casualties, whilst the army suffered 19 dead and 27 wounded. Meanwhile, some rebels took over a civilian hospital; subsequently stormed by government soldiers, the rebels were rounded up, tortured and 22 were executed without trial. Accompanied by 19 comrades, Castro set out for Gran Piedra in the rugged Sierra Maestra mountains several kilometres to the north, where they could establish a guerrilla base. Responding to the attack, Batista's government proclaimed martial law, ordering a violent crackdown on dissent, and imposing strict media censorship. The government broadcast misinformation about the event, claiming that the rebels were communists who had killed hospital patients, although news and photographs of the army's use of torture and summary executions in Oriente soon spread, causing widespread public and some governmental disapproval.
Over the following days, the rebels were rounded up; some were executed and others – including Castro – transported to a prison north of Santiago. Believing Castro incapable of planning the attack alone, the government accused Ortodoxo and PSP politicians of involvement, putting 122 defendants on trial on 21 September at the Palace of Justice, Santiago. Acting as his own defense counsel, Castro cited Martí as the intellectual author of the attack and convinced the three judges to overrule the army's decision to keep all defendants handcuffed in court, proceeding to argue that the charge with which they were accused – of "organizing an uprising of armed persons against the Constitutional Powers of the State" – was incorrect, for they had risen up against Batista, who had seized power in an unconstitutional manner. The trial embarrassed the army by revealing that they had tortured suspects, after which they tried unsuccessfully to prevent Castro from testifying any further, claiming he was too ill. The trial ended on 5 October, with the acquittal of most defendants; 55 were sentenced to prison terms of between 7 months and 13 years. Castro was sentenced on 16 October, during which he delivered a speech that would be printed under the title of History Will Absolve Me. Castro was sentenced to 15 years' imprisonment in the hospital wing of the Model Prison (Presidio Modelo), a relatively comfortable and modern institution on the Isla de Pinos.
Fidel Castro