Final answer:
Castro led a revolutionary army to overthrow Fulgencio Batista in Cuba, establishing a Marxist government and seizing control on New Year's Day 1959.
Step-by-step explanation:
Castro drove his revolutionary army into the capital of Cuba. The person whom Fidel Castro overthrew to get to power was Fulgencio Batista. The Cuban Revolution, which was led by Castro and his fellow revolutionaries, including his brother Raúl Castro and Che Guevara, began in the remote Sierra Maestra and successfully culminated in Batista’s flight on December 31, 1958, with Castro seizing power on New Year's Day 1959. Castro's government, characterized by its strong Marxist ideologies, faced opposition from landowners and former Batista supporters, some of whom were executed for their resistance.
Moreover, Castro’s alignment with the Soviet Union during the Cold War and his subsequent nationalization of foreign and domestic assets were contentious moves that ultimately led to strained relations with the United States.