Doctor Who is a British science-fiction television programme broadcast by the BBC since 1963. The programme depicts the adventures of a Time Lord called the Doctor, an extra-terrestrial being who appears to be human. The Doctor explores the universe in a time-travelling spaceship called the Tardis. With various companions, the Doctor combats foes, works to save civilisations, and helps people in need. Beginning with William Hartnell, thirteen actors have headlined the series as the Doctor; in 2017, Jodie Whittaker became the first woman to officially play the role on television.