Doctor Who debuts with anti-war message

The next series of BBC's Doctor Who debuts on Christmas Day in Britain with an anti-war message.

"It's Christmas Day, a day of peace," said writer Russell Davies.

The episode, The Christmas Invasion, also features the debut of David Tennant as the 10th incarnation of time lord Doctor Who.

Tennant, 34, who appears in the latest Harry Potter movie, replaces Christopher Ecclestone who bowed out at the end of the last series.

Billie Piper, 23, continues to play the Doctor's assistant, Rose Tyler.