The Philippines has declared a 10-day period of national mourning for the former president Corazon Aquino.
In a statement issued on Saturday, President Gloria Arroyo praised Mrs Aquino for "restoring democracy and rule of law to our nation at a time of great peril".
Mrs Aquino, 76, was diagnosed with colon cancer in March last year and underwent chemotherapy and surgery. She was admitted to hospital in June.
Her son, Senator Benigno Aquino Jr., announced her death on national television on Saturday, saying she died at 3.18am (1918 GMT Friday) of cardio-respiratory arrest.
The widow of former Senator Benigno "Ninoy" Aquino, Mrs Aquino became president when a bloodless "people power" uprising in 1986 deposed former dictator Ferdinand Marcos after 20 years of martial law and communist insurgency.
The BBC reports Mrs Aquino withstood several coup attempts, protected the country's fledgling democracy and freed political prisoners.
She framed a new constitution, overhauled the electoral process and opened peace talks with insurgent groups.
In retirement, she was a vocal critic of corruption in government and until she was diagnosed with cancer in March last year, led street protests against President Arroyo.
She had repeatedly called for the resignation of Mrs Arroyo, once a protege, whose nine-year presidency has been marked by massive corruption and allegations she has enriched her family using her office.
Former Aquino aide and press secretary Teodoro Locsin, who is also a close family friend, openly wept on television.
"The purity, the nobility, never failed. She never asked for anything in return," Locsin said.
He said more than anything else, Mrs Aquino removed the "centre of corruption in government, because she would not be corrupt."
In the capital Manila, people attended vigils and lit candles as churches held requiem masses.