Pandad IV

Pandad IV (PROSE: The Legacy of Gallifrey) led the Time Lords as President of the Council when their power was being depleted by Omega.

History
The President presided over the trial of the Second Doctor that resulted in his exile to Earth and forced regeneration into his third incarnation. (TV: The War Games; PROSE: The Three Doctors) Other accounts indicated that it was Councillor Goth that presided over the trial, with Socra and Adelphi also present. (PROSE: The Legacy of Gallifrey, Future Imperfect)

While the identity of the aggressor was unknown, (TV: The Three Doctors) as Omega's anti-matter universe was beyond the reach of the Matrix, (PROSE: The Legacy of Gallifrey) the President decided to use the last of their power to summon the Doctor's first two incarnations to help the current third incarnation to resolve this crisis. (TV: The Three Doctors)

His decision to break the Laws of Time met with criticism from his Chancellor, but the President had faith in his gamble since the Time Lords didn't have any better solution since the energy drain was difficult for them to sort out.

After this gamble proved successful, the President rescinded the Third Doctor's exile on Earth and restored his ability to travel through time and space, (TV: The Three Doctors) having been advised to do so by his High Chancellor Socra, who, when the President demanded an explanation, revealed to him the existence of (and his allegiance to) the Celestial Intervention Agency. Pandad decided to keep it secret from the populatiion despite the CIA's offer to go public, feeling that it might risk lessening the Gallifreyan people's faith in the Presidency.

The same President Pandad IV (PROSE: The Legacy of Gallifrey) fell victim an an experiment conducted bt the Rani. It had resulted in some of her lab mice growing to an enormous size: The mice then ate the President's pet, a cat, and bit the President himself, triggering a regeneration. The Rani exiled herself and became a renegade as a result of the incident. (TV: The Mark of the Rani) This ended the tradition of Lord Presidents of the Time Lords possessing intelligent cats for pets and advisors, a tradition which had begun with Rassilon himself and would not be brought back until Flavia (PROSE: The Legacy of Gallifrey) became Acting President after the Fifth Doctor ran off on the Time Lords. (TV: The Five Doctors)

Behind the scenes
The novelisation of The Three Doctors stated that the President in that story was also Bernard Horsfall's character, the First Time Lord, in The War Games, presumably in a prior regeneration. Doctor Who and the Doomsday Weapon seemed to support this version of events by establishing First Time Lord as a rank synonymous with Lord President.

The matter was confused somewhat when The Deadly Assassin was first broadcast after these two stories were published featuring Horsfall as Chancellor Goth. Common theory stated that Horsfall's two Time Lord characters were one and the same which ignored the previous revelation, eventually being written into a valid source by Gary Russell in the 1985 short story The Legacy of Gallifrey.

Llywydd (The Three Doctors)