Keeper of the Matrix
The Keeper of the Matrix, formerly known as the Coordinator of the Matrix (PROSE: The Eight Doctors) and also called the Keeper of the Record of Time, (PROSE: Mindwarp) was the Time Lord responsible for watching over the Matrix. They kept the Key of Rassilon – the only key to the Matrix – on their person at all times, except on occasions when inspection or maintenance of the Matrix was to be performed by other "qualified people". (TV: The Ultimate Foe)
The Keeper of the Record of Time was the head of a small group of Matrix keepers. Narvin referred to them as a "little clique". They spent much of their time in the catacombs and sought to read truthful timelines from the Cloister Wraiths. Narvin believed it was a bad sign to see the Keeper outside the catacombs, as they only got involved with the daily business of the Capitol if something "big" and "worrying" was happening. (AUDIO: Erasure)
Individuals
Engin served as Coordinator of the Matrix for quite some time. (TV: The Deadly Assassin) He retired whilst Flavia served as Acting President, instead sitting as an Independent on the High Council. The office's title was afterwards changed to "Keeper". (PROSE: The Eight Doctors)
There was an unspecified Keeper of the Record of Time when Narvin was a Sub-Coordinator under Vansell. She told Vansell it was Narvin’s "destiny" to go to Bellascon. (AUDIO: Erasure)
Zon was the Keeper at the time of the Sixth Doctor's trial. He was taken over by the Valeyard. (TV: The Ultimate Foe)
Engin was once again the Keeper by the time of the Last Great Time War. (COMIC: Sky Jacks)
Councillor Volstrom consulted the Keeper during the Doom Coalition crisis. (AUDIO: Songs of Love)
Behind the scenes
The Keeper of the Matrix outfit used in The Ultimate Foe was bought by Andrew Beech at some point prior to 1992. That year, Beech played himself wearing the costume in the parody TV story Summer Scene.
