Castro resigns as president, state-run paper reports

HAVANA, Cuba (CNN) -- Fidel Castro announced his resignation as president of Cuba and commander in chief of Cuba's military Tuesday, according to a letter published in the state-run newspaper, Granma.

The resignation ends nearly a half-century of iron-fisted rule that inspired revolutionaries but frustrated 10 U.S. presidents.

Castro revealed his plans without notice by publishing a letter in the middle of the night in state-run newspaper Granma.

"I will not aspire to, nor will I accept the position of president of the council of state and commander in chief," Castro wrote. "I wish only to fight as a soldier of ideas. ... Perhaps my voice will be heard."