FACTBOX: Castro sister a fierce critic of Cuba communist rule

(Reuters) - Juanita Castro, the younger sister of Cuban President Raul Castro and former leader Fidel Castro, has long been a fierce critic of her brothers' communist rule over the Caribbean's largest island.

The Castro sibling, 76, who left Cuba in 1964 to live in exile in Miami, is this week publishing a book in Spanish entitled "Fidel and Raul, My Brothers, the Secret History," a memoir of her recollections of her two famous brothers.

On the eve of the publication, she told a Spanish-language TV station on Sunday that she had collaborated with the U.S. Central Intelligence Agency against her brothers' rule in Cuba before going into exile in Miami in 1964.

Former leader Fidel Castro, 83, who brought communism to Cuba after leading the 1959 revolution, and ruled the island for nearly half a century, last year handed over the presidency to his younger brother Raul Castro, 78.

Here are some facts about Juanita Castro:

* Juanita Castro was born at the Castro family home at Biran in eastern Cuba on May 6, 1933, the fifth of seven children born to Angel Castro and Lina Ruz Gonzalez. She is seven years younger than Fidel and two years younger than Raul.

* She supported her brothers' guerrilla war to overthrow dictator Fulgencio Batista, collecting funds to help finance the struggle, and in the first year after the triumph of the 1959 Revolution she managed a hospital.

* She became disillusioned with her brother Fidel Castro's shift to communism, which she calls a "betrayal" of the democratic principles he originally claimed to espouse. She says this caused a family rift, with her speaking out against the direction of the Revolution and its alignment with the Soviet Union.

* The last time she saw Fidel was in 1963 after their mother died from a heart attack at her house. They argued and she says she never spoke to him again after that.

* In 1964, she left Cuba for Mexico and then settled in Miami, the center of the Cuban exile community. In June 1965, she testified before a U.S. Congress Committee of Un-American Activities that her brother Fidel "betrayed and deceived the Cuban people" by espousing communism. She said he hated the United States obsessively, and had transformed Cuba into a "colony of Communist imperialism".

* For more than three decades, she lived quietly running a community pharmacy in Miami, before selling it in 2006 to retire.

In 1992, she sent a letter to Fidel from Madrid, asking him to surrender his regime and listen to reason.

When Fidel fell seriously ill in 2006, she criticized the Miami exile community after thousands celebrated the announcement of her brother's failing health. "He's my brother, and that's that," she told one interviewer.

* Juanita Castro filed, and won, a 1998 lawsuit in a Spanish court against Castro's illegitimate exiled daughter Alina Fernandez, for her autobiography "Alina: The Memoirs of Fidel Castro's Rebel Daughter." Juanita said the book libeled her and Fidel's parents.

* "My life's not exceptional. It's true that I'm the sister of the dictator, but many other families have also been split between supporters and opponents of the regime," she said in 2006.

(Reporting by Pascal Fletcher, editing by Jackie Frank)