India's Congress party, which has swept back to power, was formed in 1885 and spearheaded the drive to free the nation from British rule.
Jawaharlal Nehru (L) and Mahatma Gandhi led India into independence
Its initial leading light, Mohandas Karamchand Gandhi, later Mahatma, began the link between the names of Gandhi and Congress.
But the dynasty of politicians and prime ministers that Congress has spawned is more properly called Nehru-Gandhi.
India's first prime minister after partition, Jawaharlal Nehru, and subsequent premiers Indira, Rajiv - and not now, it seems, Sonia - Gandhi were not related to Mahatma.
Nehru's daughter - Indira - gained the dynastic name from her husband Feroze Gandhi.
Mahatma remains the soul of Congress - Mahatma is an honorific (meaning Great Soul) that was conferred by the Indian people.
Born in October 1869 in Porbandar, Mohandas Gandhi developed a method of direct social action based upon the principles of courage, non-violence and truth.
He believed passive resistance and civil disobedience were the most appropriate methods for obtaining political and social goals.
Back in 2000 he topped a BBC News Online poll as the greatest man of the past 1,000 years, pushing Leonardo da Vinci and Jesus Christ into second and third respectively.
He lived to see his dream of independence, but also partition, which he did not support.
In 1948 he was assassinated by a Hindu fanatic who opposed his tolerance for all creeds and religions.
One of Mahatma's early Congress allies was Motilal Nehru, who died in 1931.
Sikhs assassinated Indira after she ordered the Golden Temple attack
On independence, Congress turned to his son, Jawaharlal, to take on the responsibility of being India's first prime minister.
He ruled for 17 years until his death in 1964 and set down the guiding principles for the party while in power - secularism, socialism and non-alignment in foreign policy.
Two years after his death, his only child - Indira - took up the Congress torch as prime minister.
She ruled for 15 years from 1966-77 and 1980-84, leading India into the 1971 war with Pakistan that led to the creation of Bangladesh.
Her campaign against Sikhs seeking independence in Punjab was equally controversial.
She ordered the attack on their holiest shrine, the Golden Temple in Amritsar in 1984, that left 450 people dead.
Five months later, Indira Gandhi was shot dead by her Sikh bodyguards.
The assassination threw the dynasty into confusion and although it won the following election on a huge sympathy vote, the succession was an unhappy one.
The body of Rajiv after his killing in 1991 by a suicide bomber
Indira's younger son, Sanjay, had taken more of a political role and was being groomed for office, but died in an air crash in 1980.
So Rajiv became India's youngest prime minister.
The nation desperately needed modernisation and a slimmer bureaucracy but Rajiv's attempts at reforms fell foul of the Bofors arms procurement scandal.
In 1989, Congress was booted out - but two years later Rajiv had turned things around and was tipped to win elections. He was assassinated in a suicide bomb attack blamed on Sri Lanka's Tamil Tiger rebels.
Without a Gandhi at the helm, Congress seemed to drift.
Although it had periods in office in the mid-1990s under two non-Gandhi premiers, they were fractious affairs dominated by minority rule.
Sonia Gandhi had embraced as private a life as possible, mourning her husband Rajiv's death, but Congress turned to her seemingly in desperation to lead it out of the wilderness.
Initial signs were not good as her political inexperience seemed more important than the charisma surrounding the family name.
The future? Rahul (L) of Congress and Varun of the BJP
Her Italian background also put off many politicians.
But Congress stood by its Gandhi heritage and on Thursday the party's wheel of fortune turned again.
As for the future, both Sonia's daughter, Priyanka, and son, Rahul, have been active campaigners this time.
Rahul, indeed, won a landslide in his family constituency of Amethi and at 33 it could be just the start of a long career.
Could the same be said of Varun Gandhi?
The son of Sanjay, Varun embraced the ruling Bharatiya Janata Party in February and although too young at 24 to stand, he campaigned for the BJP, taking on his cousins Priyanka and Rahul.
His mother, Maneka, was estranged from the family after her husband Sanjay died and has also joined the BJP.
Perhaps it could be said that whatever the result of elections, the Gandhi-Nehru dynasty would continue in power.
But Thursday's startling victory for Sonia had appeared to shore up that age-old Gandhi-Congress link.
What happens now that Sonia has turned down the job of prime minister? Time will tell.