The Time Lords are a race of humanoids originating on the planet Gallifrey, seen in the British science fiction television series Doctor Who. Time Lords are so called because they are able to travel in and manipulate time through prolonged exposure to the time vortex.
Details of the history of the Time Lords in the television series are sketchy and, as is usual for Doctor Who continuity, fraught with supposition and contradiction. This history covers the various versions given on screen and in the spin-off media based on the television series.
What little has actually been established on screen, arranged roughly in chronological order, is as follows:
The Time Lords become the masters of time travel when one of their number, the scientist Omega, creates an energy source to power their experiments in time. To this end, Omega uses a stellar manipulation device, the Hand of Omega, to rework a nearby star into a new form to serve as that source. Unfortunately, the star flares into a supernova, then collapses into a black hole. Omega is thought killed in the explosion, but somehow survives in an antimatter universe beyond the black hole's singularity.
The founder of Time Lord society, however, and its most revered figure, is Rassilon. Rassilon's name is used frequently throughout Time Lord legend and culture, and is applied to many artifacts of power. Rassilon takes a singularity (assumed by fans and the spin-off media to be the same one as Omega's) and places it beneath the Time Lords' citadel on Gallifrey. This perfectly balanced Eye of Harmony then serves as the power source for their civilisation as well as their time machines.
The early part of Time Lord history is known as the Dark Time, when the first Time Lords abuse their powers over time by manipulating lesser species. Among these abuses is the use of the Time Scoop to abduct beings from throughout history to participate in gladiatorial games (with the exception of such races as Daleks and Cybermen who "play the game too well" and are thus considered too dangerous to be used) in an area of Gallifrey known as the Death Zone.