Doctor Who Regenerates: Peter Capaldi Is 12th Doctor

The new Doctor Who, the twelfth regeneration of the iconic time-and-space traveller, has been revealed as Peter Capaldi, better known as the foul-mouthed political advisor Malcolm Tucker from movie In The Loop. The BBC's big announcement, fueled by a social media campaign and various teasers, saw almost 7m Brits tune in on Saturday evening for a one-off show to introduce the new actor, though Doctor Who's international appeal means interest outside of the UK has been just as strong: and just as controversial.

The 12th Doctor is a perhaps unusual direction for the hit BBC show to take, given the marked differences between Capaldi and the recent actors to play the role. Matt Smith, who played the 11th Doctor, was the youngest actor to do so, though Capaldi is – at 55 – older than Smith, 10th Doctor actor David Tennant, and 9th Doctor actor Christopher Eccleston, who led the relaunched series back in 2005.

The trend to look to younger actors – despite the regenerating Time Lord character itself being more than 900 years old in-universe – was part of what had been seen as an ongoing attempt to curry favor among the youth audience. Sure enough, the announcement that Capaldi was to take on the role led to furore online, with many unhappy that an older actor had been picked.

However, there's no shortage of past examples for older actors playing the Doctor. The first three Doctors, in fact, in the show's original run from 1963 were all older, more curmudgeonly types, with younger actors gradually filtering in during the mid-70s.

Matt Smith will leave the role at the end of 2013, with his final appearance being in the Christmas special. Exactly what will trigger the regeneration between 11th and 12th Doctor is unknown, with the BBC keeping the plotlines a tightly-guarded secret.