Hilary Mantel 'astonished' at Costa win for Bring Up the Bodies

Author Hilary Mantel has said she is "astonished" and "enormously gratified" at winning the Costa Book of the Year award.

It is the latest in a series of successes for Mantel, whose historical 2012 novel Bring Up the Bodies also won the Man Booker prize. Her previous novel, Wolf Hall, also won both prizes.

She spoke to the BBC's Nick Higham about what drew her to the character of Thomas Cromwell.