Peter Davison (5th Doctor) Probably the actor with the most difficult task in taking on the role - in having to follow Tom Baker. Being the youngest Doctor until Smith, Davison also struggled with perceptions as to what the Doctor should be, a problem not helped by seeming to be more of a big brother to his companions. However, he successfully gave his Doctor the sense of being an old man inside a young man, which made his struggles with authority more credible, and his interpretation is one that has aged better than many.