Raul Castro, who is retiring from high public office, for most of his life toiled in the shadow of his older brother, Fidel Castro. Yet he also played a key role in Cuba's 1959 leftist revolution and the preservation of Cuban socialism.

While Fidel was the charismatic leader who rallied Cubans to defend the revolution and defy the United States, Raul (above), 89, built the military into a formidable fighting force that saw off enemies including a US-backed invasion at the Bay of Pigs.

Later, after the fall of former benefactor the Soviet Union sent Cuba into...