The BBC has announced that the 11th Doctor Who, Matt Smith, will leave the show at the end of the year, with his final episode being the 2013 Christmas special. No word yet on who will replace him.

"Doctor Who has been the most brilliant experience for me as an actor and a bloke, and that largely is down to the cast, crew and fans of the show," Smith said in a statement. "I'm incredibly grateful to all the cast and crew who work tirelessly every day to realize all the elements of the show and deliver Doctor Who to the audience. Many of them have become good friends and I'm incredibly proud of what we have achieved over the last four years."

Smith replaced David Tennant as the good Doctor in 2010, and is the youngest actor to have played the role. Other actors who have played the role over the years include Tom Baker, Colin Baker, William Hartnell, Christopher Eccleston and Sylvester McCoy.

"It's been an honor to play this part, to follow the legacy of brilliant actors, and helm the Tardis for a spell with 'the ginger, the nose and the impossible one,'" Smith said "But when ya gotta go, ya gotta go and Trenzalore calls. Thank you guys."

Doctor Who marks its 50th anniversary in November with a special episode, which the BBC says Smith has already filmed.

"Of course, this isn't the end of the story, because now the search begins," said Steven Moffat, lead writer and executive producer. "Somewhere out there right now - all unknowing, just going about their business - is someone who's about to become the Doctor. A life is going to change, and Doctor Who will be born all over again! After 50 years, that's still so exciting!"