1967
A small but lasting change was made to the series in this year, when the Doctor's face was included in a revamped opening sequence. A tradition that would remain throughout the next six Doctors, it was brought back during last year's Christmas Special, its first appearance since the revival of the series. Continuing their own individual success, Dalek creator Terry Nation also attempted to launch a separate spin-off series for his beloved exterminators, but this never came to be. Probably for the best in all fairness, as you can have too much of a good thing, something proved when even their occasional Doctor Who appearances became somewhat repetitive over the next few years.
1968
The most trusty and loyal of all companions, Alistair Gordon Lethbridge-Stewart, known more commonly as the Brigadier, first met the Doctor this year in The Web of Fear. The two were pitted against The Great Intelligence in the tunnels of the London Underground. Although only one episode was believed to have survived, they rest were found earlier this year in Nigeria. The Brigadier soon returned again in the eight episode serial The Invasion, and this time was backed up by the force of UNIT in their first appearance. When trying to peer into a pipe in Fury From The Deep, the Doctor also uses something that some of his later incarnations would rely on rather heavily, and the Sonic Screwdriver is introduced.
1969
It may sound strange now, but although his alien origins were hardly denied, it would be six years into the show's run before it even mentioned that the Doctor was from a race known as the Time Lords. In the longest serial of the series, the 10 episode story The War Games revealed that the Doctor was in fact a fugitive on the run from his (still unnamed) home planet, and in their first appearance his own people put him on trial for interfering in the history and development of other races. This resulted in companions Zoe and Jamie having their memories wiped, and in a form of ironic punishment the Doctor is sent to Earth, exiled there to help against alien invasions.