Fidel Castro was able to lead the Cuban Revolution thanks to several leadership qualities. First among these was his charisma. He was a dynamic person who knew how to inspire his followers through the force of his personality. Castro's enthusiasm for his cause showed through in all his actions and words. He was gifted in rhetoric and public speaking. He never came off as cynical or pessimistic. His fellow revolutionaries were convinced that Castro's motives were true, and this helped them believe in his cause all the more strongly.
Castro was further able to gain the support of his followers because he knew how to connect with everyday Cubans. Despite growing up in a wealthy family, Castro honed the image of a man of the people. He got down onto the level of his people and made it clear that his cause was their cause. In this way, he led by example. This placed him in stark contrast to Batista, who ruled through coercion and a heavy hand.
In addition to all this, Castro's ruthlessness with his opposition was a quality that propelled him into power. Castro did not shy away from imprisoning and executing in large numbers those who stood against him. While he rewarded his supporters, he severely punished his enemies. This broke the will of Batista's forces, paving the way for Castro's rise to power.