Castro, Fidel (Fidel Alejandro Castro Ruz), 1926-, Cuban revolutionary, premier of Cuba (1959-76), president of the Council of State and of the Council of Ministers (1976-2008). As a student leader and lawyer, Castro opposed the dictatorship of Fulgencio Batista y Zaldívar. On July 26, 1953, he led an unsuccessful attack on an army post in Santiago de Cuba and was imprisoned. Released (1955) in a general amnesty, he went to Mexico where he organized the 26th of July movement. In Dec., 1956, he landed in SW Oriente prov. with a small group of rebels. Castro and 11 others, including his brother Raúl and Ernesto "Che" Guevara, survived the initial encounter and hid in the mountains of the Sierra Maestra. There, they organized a guerrilla campaign that eventually toppled the Batista regime on Jan. 1, 1959.

Widely hailed as a liberator, Castro proved to be a charismatic, though sometimes ruthless, leader. He proceeded to collectivize agriculture and to expropriate native and foreign industry. He instituted sweeping reforms in favor of the poor, disenfranchising the propertied classes, many of whom fled. In Dec., 1961, he declared himself to be a Marxist-Leninist and veered the revolution toward the Soviet Union and the socialist block. Tensions with the United States steadily grew. In 1961, the United States organized an invasion of Cuban exiles at the Bay of Pigs (see Bay of Pigs Invasion). A year later, the world came to the brink of nuclear war when the Soviet Union placed nuclear weapons capable of reaching the United States on the island (see Cuban Missile Crisis). The crisis was defused following negotiations between the superpowers and the removal of the missiles. For Castro, it was a humiliating, though temporary, defeat.

Castro's goal of extending the Cuban revolution to other Latin American countries suffered a setback with the capture and death (1967) of "Che" Guevara in Bolivia. Yet pro-Castro groups appeared throughout the region, and the Sandinista revolution triumphed in Nicaragua in 1979. From 1975 to 1989, he also sent troops to support the socialist government of Angola. In 1980, Castro opened the port of Mariél and encouraged dissidents to leave. Tens of thousands of Cubans left for the U.S. mainland on makeshift rafts and boats; most were granted political asylum by the United States.

Although Castro maintained political independence from the Soviet Union, the Cuban economy came to depend on billions of dollars in Soviet aid. With the collapse of the Soviet Union in 1991, Cuba entered a crisis period. Popular unrest grew in the face of extreme austerity measures. In desperate need of foreign capital, the regime opened Cuba somewhat to foreign investment and promoted tourism, while clamping down on dissent. In mid-2006, Castro underwent surgery and stepped aside as president temporarily; his brother Raúl Castro became acting president. Castro did not resume his presidential duties before the next election, and in 2008 he declined to stand for reelection. He retained his post as leader of the Cuban Communist party. Although his prestige has diminished, Castro remains a symbol of social justice and revolutionary progress for many Cubans.