For many fans, Matt Smith was the first Doctor. Taking on the role of the renegade Time Lord in 2010, Smith brought his own unique flair to Doctor Who and single-handedly spawned a worldwide obsession with bow ties.
Matt Smith bowed out as the Doctor in 2013, a season earlier than initially planned. He was replaced by Peter Capaldi, the twelfth actor to take on the role. However, since departing the series, Matt has made it clear to the world that he has forever regretted his decision and would give anything to return.
With Capaldi expected to regenerate at the end of next season, it's likely the search for his successor will begin very soon. Steven Moffat, the current showrunner of Doctor Who, is also confirmed to be leaving at the end of 2017, though plans to see the season through right up to the very end. He's also very keen on the idea of Matt Smith returning.
When asked about the prospect, Moffat said:
"Matt is quite open about how much he misses it, and how much he wishes he hadn't left."
Likewise, Matt Smith himself has frequently expressed interest in returning to the role, saying just last year:
"They will ask me back one day, won't they?"
Matt has already reprised his role on the show since Peter Capaldi's takeover, appearing on the other end of a phone call to Clara, the Doctor's companion, during the season eight premiere.
So if the cast and crew are on board with the idea, what's stopping them? Matt was hugely popular when he was in the TARDIS and his departure was met with waves of sadness and disappointment worldwide. A huge chunk of the fans would love to see him back, but bringing him back may not be quite as easy as you'd like to think.
Firstly, it's unlikely the BBC would bring back an already well established actor when there are so many undiscovered stars perfect for the role. The role of the Doctor is a highly sought after position and giving it to the same guy twice is hardly fair.
Secondly, despite showing a lot of interest in the idea, Matt Smith may not actually be available to take on such a high pressure role in the coming years. Following his run on Doctor Who, Matt has appeared in several high budget blockbusters such as Terminator: Genisys and Pride and Prejudice and Zombies and has several further projects lined up. Factor in his blossoming career on stage, including the fantastic American Psycho: The Musical, and you'll find Matt's got quite a busy schedule lined up.
However, as far as the Doctor Who canon is concerned, the Eleventh Doctor could easily return whenever he wants. Way back in 2008, David Tennant proved that it was possible to regenerate back into the same body if you cheat a little bit and divert some excess energy to prevent a change. However, with Capaldi sandwiched in between, this may not be possible.
The show has also established that regeneration doesn't always have to be random. In the short episode "The Night of the Doctor", the Eighth Doctor (Paul McGann) chooses to take on the persona of John Hurt's War Doctor to help stop the Time War. If you go back even further, the Second Doctor's regeneration into Jon Pertwee was controlled by the Time Lords as a punishment. And more recently, Peter Capaldi's appearance was controlled subconsciously by the Doctor himself to resemble Caecilius, reminding him that he can save anyone.
And finally, in the 50th Anniversary Special, "The Day of the Doctor," Tom Baker himself all but confirmed that the Doctor would return to some of his previous regenerations in his older age. As the mysterious Curator, Baker implied that he was one of the last forms the Doctor would take as well as one of the first. And if he can come back, what's stopping the Doctor from choosing a more recent body instead?
But right now, we've still got at least another year of Peter Capaldi and a whole host of other projects from Matt Smith. There's still every chance he could return to Doctor Who, though it may be in a different role altogether. The actors for both the Sixth and Twelfth Doctors have appeared on the show as different characters before taking the top role, so who's to say Matt won't do the reverse?
Doctor Who will be returning this Christmas and then again in late 2017.