From a virtual unknown outside his home state of Illinois to the most powerful man on earth, Barack Obama has come a long way in less than two years with his historic election as the first African American US president.
But even before the youthful Democratic senator vanquished Republican John McCain, a Vietnam War veteran and a national hero, Obama signalled momentous change in America's political scene as the first black person to become the presidential candidate of a major US party.
Obama himself described as a "defining moment for our nation" his clinching the Democratic nomination after a long and gruelling battle against former first lady Hillary Clinton a contest that gripped the US from January to June 2008.
Obama, 47, who has been able to attract crowds of 100,000 people or more to his rallies and generate a buzz seldom seen in US politics with his message of change, is an ardent admirer of Mahatma Gandhi, the pioneer of Satyagraha resistance to tyranny through mass civil disobedience.
"In my life, I have always looked to Mahatma Gandhi as an inspiration, because he embodied the kind of transformational change that can be made when ordinary people come together to do extraordinary things," he wrote in an article.
"That is why his portrait hangs in my Senate office; to remind me that real results will not just come from Washington, they will come from the people."
Obama, who has promised to renew American diplomacy to meet the challenges of the 21st century by rebuilding alliances and expressed a willingness "to meet with all nations, friend and foe, to advance American interests", has said that India will be "top priority" in his presidency.
As Obama said in a recent interview with IANS, he believes that "India is a natural strategic partner for America in the 21st century and that the US should be working with India on a range of critical issues from preventing terrorism to promoting peace and stability in Asia."
A former aide told IANS that Obama has a soft corner for the Indian American community and learnt tales of the Indian epic Mahabharat from his mother who has visited South Asia. He is also believed to like Indian food.
Entering politics in 1996 with an unopposed election to the Illinois state Senate, Obama burst on to the national stage in 2004 with an electrifying keynote address to the party forum in Boston calling for an end of America's divisive politics.
"There's not a liberal America and a conservative America; there is the United States of America. There's not a black America and a white America and Latino America and Asian America; there is the United States of America," he told the delegates then.
There was no looking back for the son of a black father from Kenya and a white mother from Kansas after that. In the afterglow of the Boston convention he made it to the US Senate with a wide margin just four years after losing badly in his first attempt to enter Congress.
But Obama had set his sights higher. Just three years in the Senate, he formed a presidential exploratory committee in January 2007 and one month later launched his presidential campaign on the steps of the old Statehouse in Springfield, Illinois.
Facing him was an array of seasoned contenders, including his vice-presidential pick Joe Biden, 2004 Democratic vice presidential candidate John Edwards, New Mexico Governor Bill Richardson and of course the formidable Hillary Clinton, viewed as the party's "inevitable" choice.
Slowly eroding the former first lady's large lead in opinion polls, Obama cracked Clinton's aura of inevitability with a victory in the Iowa caucuses in January and went on to win the Democratic nomination.
Obama was only two when his father left Hawaii to pursue a degree at Harvard University and later returned to Kenya alone, where he worked as a government economist, and the couple divorced. Obama saw him only once again when he was 10.
When Obama was six, his mother married an Indonesian man and the family moved to Jakarta. But four years later he moved back to Hawaii to live with his maternal grandparents. His grandmother died on Monday.
In his 1995 autobiography, "Dreams from My Father", Obama describes a troubled adolescence in which he struggled with his biracial identity. He acknowledges that he used marijuana and cocaine.
After high school, Obama attended college in Los Angeles, California, and New York before working as a community organiser on the south side of Chicago, Illinois, from 1985 to 1988.
He attended Harvard Law School, where he became the first black president of the prestigious Harvard Law Review, and returned to Chicago after graduating in 1991 to work as a civil rights lawyer and teach constitutional law.
There he met his future wife, Michelle Robinson, a Chicago lawyer. They have two young daughters, Malia and Sasha.