Joe Biden has named Kamala Harris as his running mate, making the California senator the first Black and South Asian American woman to run on a major political party’s presidential ticket.”I’ve decided that Kamala Harris is the best person to help me take this fight to Donald Trump and Mike Pence and then to lead this nation starting in January 2021,” the presumptive Democratic presidential nominee wrote in an email Tuesday.

In selecting Harris, Biden adds a former primary rival who centered her own presidential bid on her readiness to take on Donald Trump and show Americans she would fight for them. She rose to national prominence within the Democratic Party by interrogating Trump nominees during Senate hearings, from former Attorney General Jeff Sessions to Supreme Court Justice Brett Kavanaugh.

Harris’ selection comes months after Biden committed to picking a woman to join him on the Democratic ticket. Harris, 55, is now the third woman to serve as a vice presidential candidate for a major political party, following Geraldine Ferraro as the Democratic vice presidential pick in 1984 and Sarah Palin as the Republican vice presidential pick in 2008.

Aware that his age could be a concern to some voters, Biden, 77, has said that he is “a bridge” to a new slate of Democratic leaders, and by selecting Harris, more than 20 years his junior, he has elevated a leading figure from a younger generation within the party.Biden’s selection unfolded with the utmost secrecy after a period in which he spoke with the contenders either in person or in face-to-face meetings.

After considering some 11 women for the post, he and his aides spent time on Tuesday afternoon notifying the VP candidates who he did not choose.