He was the oldest actor, starting at the age of 55, to play the Doctor in Docteur Who (1963) until David Bradley was cast to play The First Doctor in 2017's Christmas episode (as well as a small teaser at the end of the previous episode) at the age of 75. Bradley had previously played Hartnell himself in the 2013 BBC biopic An Adventure in Space and Time (2013), including reconstructions of Hartnell in the role of The Doctor. Peter Capaldi was also 55 at the time of his getting the part, but was still younger than Hartnell by a matter of months.
