Juanita Castro, the younger sister of Fidel and Raul Castro who was so opposed to their policies that she became a CIA double agent, died of natural causes in a Miami, Florida, hospital on Monday, Univision confirmed. She was 90.
Since the 1959 Cuban revolution, she was a tireless detractor of her brothers' Communist regime and fled the Caribbean country in 1964 for Miami, Florida, hoping to find a sense of community among her peers living in exile.
Instead, she found herself ostracized.
"For those in Cuba, I am a deserter because I left and denounced the regime in place. For many in Miami I amn 'persona non grata' because I am the sister of Fidel and Raul," she wrote in her memoir, "My Brothers Fidel and Raul, the Secret History."
Fidel Castro's alliance with the Soviet Union led to the 1962 Cuban Missile Crisis, a nearly two-week confrontation with the U.S. that took the world to the brink of nuclear catastrophe. Fidel Castro went on to lead Cuba until he transferred power to his brother Raul in 2006 because of health concerns.
In 2016, Fidel Castro died at 90, the same age his sister would live to.
Miguel Díaz-Canel succeeded Raul Castro in 2018, drawing to a close the brothers' near 60-year reign.
Those who knew Juanita Castro remember her work ethic. For decades, the fourth of seven children kept shop at the South Florida drugstore she owned. All the while, she remained an outspoken critic of her brothers. She had even collaborated with the CIA in an attempt to bring them down at the height of their rule, under the codename "Donna."
Journalist María Antonieta Collins, who co-authored Juanita Castro's memoir, was the first to break the news of her death.
"Today, at 90 years of age, Juanita Castro went ahead of us on the path of life and death, an exceptional woman, a tireless fighter for the cause of her Cuba," reads the Monday afternoon Instagram announcement, translated from Spanish.
The cause of her death has not yet been made public. Collins said the funeral would be private, as Juanita Castro had requested.