Barack Obama made history on 4 November 2008 when he easily defeated Republican rival John McCain to become the first black president of the United States.
He had already broken new ground in his White House campaign, as the first black candidate to become the presidential choice of either major US party.
His stirring oratory, combined with an easy charm, won him supporters in the US and admirers across the globe.
Critics, however, have started to question whether there is much substance behind his well-crafted statements of good intent.
Domestically, his first year in office has thus far been dominated by his attempts to reform US healthcare amid fierce opposition.
There the Kenyan met and married Mr Obama's mother, Ann, who was living in Honolulu with her parents.
When Mr Obama was a toddler, his father got a chance to study at Harvard but there was no money for the family to go with him. He later returned to Kenya alone, where he worked as a government economist, and the couple divorced.
When Mr Obama was six, his mother married an Indonesian man and the family moved to Jakarta.
Although his father and step-father were Muslim, Mr Obama is a Christian and attended secular and Catholic schools during the four years he lived in Indonesia, a largely Muslim country.
He then moved back to Hawaii to live with his grandparents and attend school.
Mr Obama went on to study political science at Columbia University in New York, and then moved to Chicago where he spent three years as a community organiser.
In 1988 he left to attend Harvard Law School, where he became the first African-American president of the Harvard Law Review.
During the summer vacations from Harvard, Mr Obama returned to Chicago and served internships with law firms.
It was during one such internship that he met the then Michelle Robinson, whom he went on to marry in 1992. The couple have two...