Aquino, who had been battling cancer, was 76.
"Cory" Aquino, catapulted into politics by the assassination of her husband, Benigno Aquino, successfully challenged longtime President Ferdinand Marcos and was inaugurated in February 1987 to a six-year term.
Aquino's rise to power began with the 1983 assassination of her husband, which sparked unprecedented protests against Marcos and assaults on the institutions of "constitutional authoritarianism" he had built after declaring martial law in 1972.
A civilian inquiry into the shooting of Benigno Aquino found the military, including Marcos' trusted Armed Forces Chief of Staff Gen. Fabian Ver, carried it out. A special court later cleared Ver.
Corazon Aquino and her followers insisted Marcos engineered the assassination, as well as the acquittal of those accused of it. Marcos hotly denied the accusations but could not dispel them.
Under growing U.S. pressure to revitalize the democratic processes, Marcos yielded to a demand for a snap election. He did not know his opponent would be Cory Aquino.
Marcos claimed a landslide victory in nationwide balloting Feb. 7, 1986, but Aquino supporters' claims of electoral fraud were supported by independent observers.
A year later, the day Cory Aquino took the presidential oath of office, Washington announced U.S. recognition of her government. She inherited wrenching problems from the Marcos era, including widespread poverty, a $26 billion foreign debt and a continuing communist insurgency.
She freed political prisoners and opened the presidential palace so the public could view the excesses of Marcos and his once-powerful wife, Imelda.
"I am just one of the thousands and millions of victims of the Marcos dictatorship," she said. "And I know very well that I am not the victim who has suffered the most."
The daughter of a sugar plantation owner, Corazon Cojuangco was raised with a private Catholic education and attended high schools in New York and Philadelphia, then the College of Mount Saint Vincent in New York.
The deeply religious Aquino said it was not the assassination of her husband but his nearly eight years of incarceration that had the greatest influence on her -- what she described as her "awakening."
"When all seemed hopeless, I learned I could only turn to God," she said. "Through all the crisis in my life, I really believed God would show me the way."
When she left office in 1992, the Philippines had its first peaceful transition of power in a quarter century.
Cory Aquino remained active in politics, joining the opposition to President Joseph Estrada and first supporting, then opposing the current president, Gloria Macapagal Arroyo.