A biography of Fidel Castro that covers both his formative years and his ultimate stature as a Communist revolutionary/thorn in the side of the U.S.

Looking for a well-researched, objective (as much as possible) and readable biography on Fidel Castro. I'm not looking to confirm either communist or capitalist biases, I'm just interested because I'm finishing Stephen Kinzer's book on the political history of Nicaragua and was fascinated to read about just how big a figure Castro was to revolutionaries in Latin America.