Time Lords

Season 6 (1968-1969)
The War Games

Season 10 (1972-1973)
The Three Doctors

Season 12 (1974-1975)
Genesis of the Daleks

Season 20 (1983)
The Six doctors

30th anniversary special
The Wrong doctors

Behind the scenes
Script editor Peter J Hammond threw some lines in the direction that the Time Lords were the same type of beings that the doctor fought, even though we already saw the time lords and that they weren't the same type of beings that the doctor fought. Peter J hammond would later say it would be nice to not see the Time Lords or the Homeworld.