Final answer:
Fidel Castro was a leader who transformed Cuba into a Marxist state after overthrowing Fulgencio Batista in 1959, maintained a long rule that suppressed dissent, and played a significant role in Cold War politics, most famously during the Cuban Missile Crisis.
Step-by-step explanation:
Fidel Castro was a defining figure of the 20th century, known for his role as the Cuban revolutionary leader who overthrew the regime of Fulgencio Batista. The culmination of his efforts was the seizing of power on New Year's Day 1959, a victory that resonated with many, particularly the impoverished population of Cuba who had suffered under the previous government. Castro's regime, however, soon revealed its Marxist leanings, as he implemented reforms that root from these ideologies, such as nationalizing land and businesses. Despite early promises of democracy, Castro's government never conducted free elections and was noted for its suppression of free speech and dissent, executing many of Batista's supporters, including with the help of Che Guevara
Castro's Cuba played a significant role in the Cold War, most notably during the Cuban Missile Crisis where the presence of Soviet missiles on the island led to a tense standoff between the United States and the Soviet Union. Castro's alliance with the USSR and the subsequent U.S. embargo defined Cuba's international relations for decades. Fidel Castro remained in power until 2008, becoming one of the longest-serving leaders in the world, after which his brother Raúl Castro took over until 2018. His influence extended beyond Cuba, as he supported various leftist movements and insurgencies around Latin America.