Kamala Harris made history on Wednesday when she was sworn in as Joe Biden's vice president, becoming the first woman, the first Black American and the first Asian American to hold the second highest US office. Looking ahead, Ms Harris, 56, is seen as an obvious contender for the Democratic Party's 2024 presidential nomination should Biden, 78, decide not to seek a second term. Ms Harris has yet to weigh in publicly on such speculation.
A US senator from California the past four years, Ms Harris has shattered many a glass ceiling. She served as San Francisco's first female district attorney and was California's first woman of colour to be elected attorney general.
Ms Harris has resigned her Senate seat, but she still will play a prominent role in the chamber.
The US vice president serves as Senate president, casting any tie-breaking votes in the 100-member chamber. With it split evenly between Democrats and Republicans, Ms Harris gives her party control of the Senate.
Her background in criminal justice could help the new Biden administration tackle the issues of racial equality and policing after the country was swept by protests last year.
She is expected to be a top adviser on judicial nominations.
Ms Harris is the daughter of immigrants, with her mother coming to the United States from India and her father from Jamaica.
She had her sights set on becoming the first woman US president when she competed against Joe Biden and others for their party's 2020 nomination.
Ms Harris dropped out of the race after a campaign hurt by her wavering views on healthcare and indecision about embracing her past as a prosecutor.
Mr Biden looked beyond some of the harsh words she had for him in that campaign to name her as his running mate last August.
She has proven to be a valuable and polished stand-in, appealing especially to women, liberals and voters of colour.
Ms Harris developed a deep fundraising network during her Senate and White House bids.
She was instrumental to Mr Biden's raking in record sums of money in the closing months of the campaign against Republican incumbent Donald Trump.
Her selection sparked a burst of excitement in the Democratic voter base and among the party's donors.
Accusations from liberals that Ms Harris did not do enough to investigate police shootings and wrongful conviction cases when she was California's attorney general helped doom her own presidential run but surfaced little during her time as Mr Biden's running mate.
Ms Harris defended her record, saying she had worked her whole career "to reform the criminal justice system with the understanding that it is deeply flawed and in need of repair." Prior to her selection, several Biden aides said Ms Harris was able to put to rest concerns among some in the former vice president's camp that she would be too personally ambitious to make a trustworthy partner.
"Joe and I were raised in a very similar way," Ms Harris said of Mr Biden at her October debate against then-Vice President Mike Pence.
"We were raised with values that are about hard work, about the value and the dignity of public service and about the importance of fighting for the dignity of all people."