Mrs Aquino was catapulted into politics following the murder of her husband, the prominent Senator Benigno "Ninoy" Aquino, who had been preparing to run for president.
He had already spent seven years in prison following President Marcos's declaration of martial law, with his wife as his only contact with the outside world.
Mrs Aquino said of her husband's death: "What is more important is that he did not die in vain and that his sacrifice, certainly, awakened the Filipino people from their apathy and indifference."
After winning the presidential elections in 1986, she went on to run a country deeply divided after years of martial law and communist insurgency.
She battled several coup attempts against her rule, protected the country's fledgling democracy and freed political prisoners.
She was nominated for the Nobel Peace Prize in 1986 and later received several awards and citations for her work to promote democracy and human rights.
Tribute from president
The current president of the Philippines, Gloria Arroyo, announced 10 days of national mourning.