The future guerrillas started their training programme, being careful not to attract attention. They took long walks, rowed on the lake in the Chapultepec Park, climbed the nearby hills. Ernesto joined them when he wasn't needed at his workplace and sometimes he gave medical help to his Cuban comrades. At the end of March Castro found a place in Santa Fé (the outskirts of Mexico City) where they could practise shooting. That was the moment when Ernesto gave up his research and joined his combatants to do as much practice as possible. In the evenings they studied politics and Colonel Alberto Bayo, a veteran of the Spanish Civil War, gave them lessons on guerrilla warfare.
When the group became bigger, a hidden house was bought in Chalco, some forty kilometres from the capital, so they continued their practice there. They learnt how to shoot, how to handle their weapons, and other things a guerrilla should know. Ernesto/Che became the group's head of personnel, it was him who signed the rental agreement and after a while he led the long marches at night when the combatants were walking along the hills for hours, with their heavy backpack. He even found time for playing chess with Colonel Bayo.

In June the group's activities were discovered, some of its members were taken into custody - even María Antonia whose home was searched. The Mexican newspaper Excelsior published an article that "seven communists apprehended for conspiring against Batista". Hilda with the baby was also taken into custody.  To avoid bloodshed, Castro led the police to the house, so other combatants - Che as well - were taken to the jail at Calle Miguel Schultz 136. They all were interrogated but they had been taught how to reply such questions without giving information.
Those combatants, who could stay free, managed to hide the remaining weapons and equipment, and they organised a campaign to get Castro and his comrades out of jail. Hilda brought clothes and food for Che without seeing him for two weeks. Meanwhile Che refused any help to set him free by Argentine help because he wanted to share the fate of his Cuban comrades.
In the jail the group studied, played games, read books - Che studied mathematics and economics. He could play chess with several men at the same time - memorising all the steps on the different boards.

On 9th July most of the detainees were set free - except Che, Castro, Calixto García and Jimmy Hirzel. Hirzel was set free soon, but the other three men spent several more weeks inside the jail. Castro and Che discussed their political views and their plans for the future and their close friendship improved.
On 17th July Che wrote to his mother: "I am neither Christ nor a philanthropist, I am exactly the opposite of a Christ... for the things I believe in I fight with all the weapons within my reach and I try to leave my opponent flat on the floor, instead of letting me be nailed to a cross or to any other place." He also violently rejected any possibility that he may lead such a life that his parents hoped that he would follow. The training and the jail hardened him for the revolutionary life.

On 24th July Fidel Castro left the jail - Che and Calixto followed him on 14th August. Before Castro left, Che told him that he would understand if he was left behind, but Fidel refused to leave for Cuba without him. After setting free, Che was told to leave Mexico as soon as possible, so he left the capital and hid in different Mexican places a false name.
At the end of September Castro bought the yacht Granma from its American owner and gave him money for the repair costs. Preparations were getting faster.

On 25th November 1956 at 2 a.m. the Granma left Tuxpán, with eighty-two combatants on its board (it actually had the capacity for only twenty-four people). Everyone was excited and happy - then soon seasick. Che even had a long asthma attack.
It took the Granma seven days to reach Cuba - instead of the five planned. It caused a tragedy. On the fifth day Frank País launched his uprising in Santiago to pull Batista's attention on himself so the expedition could have arrived without being noticed but as the Granma was late, the whole plan failed. The uprising was killed and the army was waiting for Castro's group.

On 2nd December at 2 a.m. at Las Coloradas the yacht was out of fuel and the combatants had to leave it, walking in the water, carrying their equipment in their hands. Che and Raúl Castro were the last to disembark. They had to wade through thorny bushes, sharp leaves and attacks of hungry mosquitos. After two hours they reached dry land, with bleeding feet, wet clothes and weapons. Some of the men were separated from the main group. Then the air force and the coastguard started their attack by shooting the rebels and the landscape.
A peasant became the guide of the combatants and they started to walk towards the mountains of Sierra Maestra, having a rest on a sugarcane field. The attacks were constant, reinforcements arrived, and even the guide betrayed the combatants. Some of the fighters died in the battle, some ran away (then were caught and killed), backpacks and weapons were lost. Some, like Ñico López, Che's first Cuban friend, were captured, tortured and killed. Even Che received a wound on his neck. It bled heavily and he was preparing for dying with dignity, when one of his friends, Juan Almeida found him, told him that it was not a lethal wound and they continued marching out of the field, now burning.

Out of the 82 fighters, only 20 survived. The survivors formed groups and tried to reach the Sierra Maestra without knowing if their leader, Castro was dead or alive. They changed clothes, wearing peasants' jackets and trousers, and hid their weapons. When they met a welcoming peasant, they could eat - otherwise they starved. Cuban newspapers were writing about the Rebel Army and even named Che, also describing "an Argentine Communist, being expelled from his country". Che loved it.
Finally by the end of December all the survivor combatants found Castro - while Batista magnified his army's victory over the rebels and spread the rumour that Che and the Castro brothers were dead. It caused huge sadness for Che's family, but his parents started to get in touch with any possible contacts and a few days later it was confirmed by the Argentine ambassador in Havana that Che was still alive. And at New Year's Eve the family received a short letter from Che, then a card, by an anonymous messenger.
In the Sierra Maestra Castro was reorganising his rebel army. His faith in himself and in the revolution was unshakable.  
On 14th January the small group attacked the La Plata barracks and won. The soldiers surrended, the officers left and the rebels obtained a lot of weapons and different kinds of equipment. Batista had to admit the rebels' existence and sent troops to encircle the Sierra Maestra.

Some peasants helped the rebels, some betrayed them. One of them, Eutimio Guerra guided the rebel army in the mountains while also betraying them to the army several times. When it was found out, he was sentenced to death by the tribunal, presided over by Fidel Castro. It was Che who executed the traitor by shooting him.
On 28th January Che had malaria. He also started to smoke cigars that helped him avoid asthma attacks.
In February his condition became so bad that he couldn't even walk so he had to stay behind. He spent this time reading and studying. After rejoining his comrades, the army attacked them and Che lost his backpack, full of books, medicine, food and his blanket that was a trophy from La Plata.
On 17th February a veteran American journalist, Herbert Matthews came to the Sierra Maestra to make an interview with Fidel Castro. It became legendary and was read by many people in several countries.

The rebel army kept marching and Che found time to cure the sick peasants and their families he met. On 28 May they attacked the garrison at El Uvero - it ended with a major victory. Che tended to the wounded of both sides and he spent the next month with the same task while recruiting new combatants from the peasants living nearby and teaching some of his fighters to read and write. He had to work as a dentist as well and he was nicknamed El Sacamuelas (The Toothpuller).  By the end of June Che and his troops joined the main column and he became a captain. On 21 July Che became Comandante Guevara so he was given the command of Columna Nr 4. (actually the second column but it was called the fourth to dupe the enemy). Celia Sanchez gave him a small star to be pinned on his beret, Fidel gave him a wristwatch.
On 31st July Che's column met the army at Bueyecito. Everything started badly: Che's weapons didn't work and by the time he repaired his machine gun, the attack ended with the rebels' victory (Ramiro Valdés's unit won it). 
In August Che set up a camp at El Hombrito, creating a logistic system for supplies, teaching people to read and write, starting a hospital, a small weapon-making and repairing factory, and a shoe-making facility. The camp also had a small farm and an oven where they could bake bread. Two students from Havana built a small dam on the nearby river to produce hydroelectric power. Che managed to create a stable base from where his men could operate over a large area.

On 29th August Che and Fidel met and their columns marched to Pino del Agua. On 30th Che's column won a victory over General Sosa's army,  while having less modern weaponry and half as many men as the enemy had (this was the battle of El Hombrito).
By the end of October Che returned to the base camp and launched the newspaper El Cubano Libre, using a 1903 mimeograph machine to print it. He wrote articles - under the pseudonym El Francotirador (Freelancer) - this nickname was given to him by Ricardo Rojo in Ecuador. 
On 29th November Che had the battle of Mar Verde that ended in a retreat. Che proved his courage again when he picked up his injured fellow-fighter in front of a dozen enemy soldiers who were so shocked by his brave appearance that they forgot to shoot at him so he could escape harmless.
When returning to the camp, Che found it totally destroyed by the enemy. He led his column to La Pata de la Mesa and created a new camp there.
On 8th December Che's left foot was wounded, a bullet was removed from it, and while he was recovering in a peasant's house (being unable to walk for almost a week), Ramiro Valdés led the column.  

In January 1958 new issues of El Cubano Libre were published, then in February the Radio Rebelde started its transmission. Che - who made it alive - sent his first words to Camilo: "Camilo: soy el Che. Camilo, aquí habla el Che." (Camilo, I am Che. Camilo, Che is speaking here.) The radio station boosted the morale of the rebel troops and it also broke the information blocade, created by Batista's announcements about the deaths of Che and the Castros and the failure of their campaign. Radio Rebelde helped the communication among the rebel columns and it informed the people about the true events. Soon it had several stations around and outside Cuba and even in Miami (USA) people could listen to its programme. (Though it couldn't be heard in Argentina.) Other countries recorded the announcements and spread the informations about the Cuban Revolutionary War.
On 16th February Che joined Fidel at the Battle of Pino del Agua, then gave an interview to the Uruguayan reporter, Carlos María Gutiérrez. (After leaving the camp, Gutiérrez visited Che's parents and even showed them the photos of Che he had taken - so after six years they could finally see how their son looked like. They were also told that Che was idolised and adored by his troops, that he was excellent as a soldier and as a strategist, that besides fighting, he also worked as a doctor and as a teacher.
A little later another journalist came to interview Che - the Argentine Jorge Ricardo Masetti and they became great friends. 
These interviews marked the beginning of the Che Guevara legend. Very few people could resist the charm of the good-looking, humble, young Argentine doctor who left a calm, comfortable life behind in order to fight for the independence of another country, while experiencing hunger, cold, diseases and other difficulties. 

In April there were no fights. Che set up a school for future guerrillas at Minas del Frío (Escuela de Reclutas Ciro Redondo - in memory of his fallen comrade), dug trenches, built fortifications, cured people, helped local women at childbirth and read as usual. This time he read Mao Ce Tung's book about guerrilla warfare and studied Cuban history.
On 9th April the 26th July Movement called a general strike to take place all over the island but it was a failure.

In May a new column was created: Columna No.8. Ciro Rendonde. Fidel put Che in charge of it. On 25th May Batista launched the Great Summer Offensive, a huge military campaign against the Rebel Army in the Sierra Maestra - it lasted till August. There were big battles and Che left teaching and curing to fight. The Offensive ended with huge losses of the army and with big victories of the rebels who lost some great fighters but won battles, lots of weapons and ammunition. Fidel decided to extend the war beyond the Sierra Maestra. Che's column had to march to Central Cuba and paralyse enemy troop movements. They left for Las Villas on 31st August.
The journey was very tough and it started badly: the plane that had carried weapons for the rebels were discovered by the army, then a cyclone came (that became a hurricane a month later), so they had to continue on foot or on horseback while carrying their heavy backpacks. They had to drink from muddly puddles, to fight the hungry mosquitos and cross the rivers on foot.
Che was a really hard taskmaster but he drove himself the hardest and he was always fair so his fellow-combatants respected and loved him.

On 9th September the columns of Che and Camilo met and soon they had to fight against the army who started to bomb the hungry, thirsty and ragged rebels. The vegetation growing in the swamp rotted their boots and they had infected, painful feet. It kept on raining, the people were sick and exhausted. Che used both words of encouragement and violent insults to keep them going until they could see the mountains of Las Villas.
On 16th October the column arrived in the Escambray mountains, then within one and a half months it captured a number of towns in Las Villas province. By 18th December the rebels captured Fomento, on 23rd Cabaiguán, on 24th Placetas where Che installed his headquarters at Hotel Tullerías and prepared for the battle of Santa Clara. The other rebel columns were also capturing more and more towns. This was the first time when Che drove - he took his chance on a jeep.

On 29th December the rebels started the battle for Santa Clara while the army was bombing them, having far more people, weapons and ammunition by their side. By radio Che asked  the population to join the rebel army, then entered the city with his troops. In the afternoon he had the armoured train of the army derailed and captured, with all the 373 soldiers, huge piles of weapons and ammunition, enough for two months, inside. During the fights Che fell off from a wall and broke his left forearm. He ran to the hospital immediately, had it plastered and rushed back to continue fighting. (The scarf, that held his injured arm, was given to him by Aleida.)
The frightened Batista told the international press that Che was dead, while Radio Rebelde was broadcasting the many victories of the rebels all over Cuba.

By the 1st January 1959 Santa Clara belonged to the rebels. Che was devastated because he lost one of his best fighters, Roberto Rodríguez (El Vaquerito), but he was happy as well because he fell in love with Aleida March, the 24-year-old brave young woman from Santa Clara. (She went to the rebel camp bringing money - the banknotes were strapping all over her body. At first Che wasn't glad to have the pretty girl in his column, but soon he could see that Aleida worked seriously and she did everything to be useful. He even gave her a weapon.)  During the fights Che saw her exposing herself to fire while crossing the street and he realised he loved her. Within a few days, they became a couple.