Sonia Gandhi stepped down as head of India's opposition Congress party Saturday after an extraordinary odyssey that transformed her from a shy housewife into the country's most powerful politician and a torchbearer for the iconic Gandhi-Nehru dynasty.
The Italian-born Gandhi, 71, was thrust into the cauldron of Indian politics after marrying Rajiv Gandhi, scion of India's political first family, in February 1968.
One of three daughters of an Italian building contractor, she arrived in India as a mini-skirt-wearing bride and converted into a sari-clad daughter-in-law, giving up her Italian citizenship for Indian nationality.
Her years in the Gandhi household when her strong-willed, autocratic mother-in-law Indira was prime minister gave her a ringside seat to India's turbulent history.
It was Sonia who cradled Indira Gandhi as she lay dying after being shot by her Sikh bodyguards in 1984.
She said she "fought like a tigress" to prevent Rajiv, a commercial pilot, from entering politics after his brother Sanjay -- Indira's first political heir -- died piloting a small plane.
After Indira's assassination, Sonia feared politics might mean a violent death for her husband too, a vision that materialised when Rajiv was killed by a Tamil suicide bomber on the campaign trail in 1991.
She then led a reclusive existence for six years, raising her two children.
But in 1998, she accepted the entreaties of Congress leaders to join the political fray and give the party a Gandhi figurehead. A year later she was elected to parliament.
In a rare television interview last year she said she had changed her mind "because of a certain duty that I felt towards my mother-in-law and my husband".
"I saw them struggle, work day and night to uphold certain values, certain principles," she said. "When it came to my call, I felt that I was being cowardly not to respond to them."
Having been raised in a Roman Catholic family near Turin, she once confessed that before meeting her husband she had "only a vague idea India existed somewhere in the world".
The pair met in Cambridge when Sonia was studying English at a language school and Rajiv was a mechanical engineering student at Trinity College. She said it was "love at first sight".
Sonia overcame stagefright to propel Congress to a surprise electoral win over the ruling Hindu nationalist Bharatiya Janata Party (BJP) in May 2004.
She barnstormed the country, addressing huge rallies who shouted "Sonia Gandhi zindabad" -- "Long Live Sonia Gandhi".
Speaking in Hindi, reading from a Roman text, she told audiences that her heart was "buried in the soil of this country".
Poised to make history as India's first-foreign born leader, but with Hindu rightwingers threatening mass protests and vowing to hound the "foreigner" out of office, she quietly declined the job of prime minister.
She was dubbed "Saint Sonia" by Indian media for giving up leadership of the world's largest democracy, an act that only enhanced the family mystique.
But as Congress party president, she remained at the heart of decision-making.
Her heavily guarded bungalow at Number 10 Janpath in the Indian capital became as vital an address to visit as the prime minister's sprawling Race Course Road residence.
Her biographer Rasheed Kidwai said it had been "an inspirational and exceptional success story".
"She understood India very well. She was successful in blunting allegations of being an outsider and history will judge her very well on that count," he said.
Sonia delivered a second, bigger victory for Congress in 2009, but the term was marred by massive corruption scandals, including a telecoms graft case that cost the country up to $40 billion.
There were also worries about Gandhi's health -- in 2011 she had surgery in the United States for an undisclosed illness thought to be cancer.
Three years later Congress suffered its worst ever election defeat to Prime Minister Narendra Modi's BJP after a campaign fronted by Sonia's son Rahul, whose political career she has tirelessly promoted.
Analysts say Sonia saw herself as torchbearer for the dynasty that has given India three Congress prime ministers -- its first Jawaharlal Nehru, his daughter Indira Gandhi and her son Rajiv -- since independence from Britain in 1947.
Such is the family's aura that many party supporters cannot conceive of a future without a Gandhi in charge, even though critics decry the need for its continuation.
"If you have a family whose earlier generations have been in politics it gives you a head start," she once said.
"But India is a democracy ... You may have an advantage at the beginning, but you have to work hard to prove yourself."