Doctor Who's 50th anniversary episode: a who's who of the cast
Matt Smith as the Eleventh Doctor
At 26-years-of-age Matt Smith was the youngest actor ever to be cast as the Doctor.
As well as famously playing the Time Lord, Matt has had stage roles in The History Boys, Murder in the Cathedral and On the Shore of the Wide World.
Now, aged 31, the Northampton-born star is making his last appearance as the Doctor during this year's Christmas special and will be handing the lead role over to Peter Capaladi.