David Tennant took on the role as the 10th incarnation of the Doctor, keeping viewers hooked for five action-packed years, and for many fans taking over as the best ever Time Lord.

But he felt his time to pass on the sonic screwdriver had come, and decided to stepped down in 2009, making his last appearance in the two-part Christmas special 'The End of Time'.

Fun fact: Tennant found out he was the new Doctor while rehearsing for the live TV broadcast of 'The Quatermass Experiment' (2005).

Head over heels with excitement, he nearly went... well, head over heels live on air, as he ran across the set!