Article published on the 2008-08-23 Latest update 2008-08-23 11:39 TU
Biden, who is 65-years-old, is of Irish-Catholic origin and is known for his no-nonsense style, with a base of support among the working-class voters who tended to back Hillary Clinton's in the primaries.
His experience could prove to be a plus, countering Republican criticisms of Obama's relative youth, or a minus, playing against the presidential candidate's promise of change.
The son of a Delaware car salesman, he studied history and political science at university, before going on to study law.
In 1966, while at Law School, he married Neilia Hunter and the couple had three children.
In 1972 he was elected to the US Senate but his wife and infant daughter were killed in a car accident, which also injured his two sons, shortly after his election. He was sworn into office at the boys' bedside, after having been dissuaded from resigning to look after the surviving children. Since then he has commuted an hour and a half each day from his home in Wilmington.
In 1978 he married Jill Tracy Jacobs and they now have one daughter.
In 1988 he was hospitalised for two brain aneurysms and could not attend the Senate for seven months. In the same year he was forced to pull out of the presidential race, after being accused of plagiarising a speech by the former leader of the British Labour Party, Neil Kinnock.
From 1987-1995 Biden chaired the Judiciary Committee. He has been behind laws on violent crime, violence against women and the international dangerous drugs trade.
In 1997 he joined the Foreign Relations Committee and chaired it from 2001-2003, being re-elected to the position in 2006, when the Democrats regained a majority in the Senate. He supported the Bush adminstration's response to the 9/11 attacks on New York and Washington, voting for the invasion of Afganistan and for the war in Iraq. He has since criticised the cost of the Iraq war and called for the "federalisation" of the country along sectarian lines.
In 2007 he entered the race for the Democratic presidential nomination but withdrew after gaining less than one per cent of the votes in the first nomination contest in Iowa. During his brief camaign, he drew accusations of patronising black people by calling Obama "the first mainstream African-American who is articulate and bright and clean and a nice-looking guy" and declared that the current presidential candidate is not yet ready to hold the office.
He has just completed a trip to Georgia, at the invitation of President Mikheil Saakashvili and has been praised by Obama for his statements on the Caucasus and Afghanistan.