9. He Is The Oldest Doctor (Sort Of)
This decade of Doctor Who is clearly one for extremes. In 2010, Matt Smith first appeared as the Eleventh Doctor and, at 27 years old when his first episode was broadcast, was deemed the youngest Doctor ever (beating Peter Davison by two years). Consequently, in 2014, Peter Capaldi's first full episode in the role debuted, making him the oldest Doctor ever. But this is where the "sort of" comes in. Capaldi is only the sole oldest Doctor if you count the actor's ages at the time their first episode came out. For instance, Capaldi was 56 upon the premiere of Deep Breath, just beating William Hartnell to the post of oldest Doctor, who was 55 when he first appeared in An Unearthly Child. However, Capaldi was still 55 when he filmed the episode which means that, in that way of counting it, he is the joint-oldest Doctor. Although that isn't counting the one off incarnations. John Hurt was even older, at 73, when he appeared as the War Doctor. And let's not get started on Tom Baker's Curator... Phew, timey-wimey indeed!