Kirsty Young's castaway is the US Ambassador to the United Kingdom, Matthew Barzun.

Born in New York City as the second of four children to Roger Barzun, a lawyer, and his wife Serita Winthrop, he was brought up in the small Massachusetts town of Lincoln. He followed in the family tradition and read History and Literature of America at Harvard University, taking a break for a year to work as a teaching assistant in Cape Town. After graduating he worked for an internet start-up company in San Francisco, where he became chief strategy officer. He left in 2004 after getting involved with fundraising for John Kerry's failed presidential campaign.

He was in the audience for Barak Obama's, 'there are no red or blue States, just a United States' speech in 2004 and subsequently went to work for him, fundraising for Obama's 2008 bid for the White House. When President Obama won, he appointed Matthew as Ambassador to Sweden only to recall him to take up the role of National Finance Chair for the 2012 re-election campaign. Matthew is credited with developing a 'low dollar' model of funding, where many pay a few dollars for tickets to political events. In July 2013, he was nominated as the new Ambassador to the UK by President Obama, a post he took up in August 2013 and which ends in January 2017.

Producer: Cathy Drysdale.