Mordee expedition

The Mordee expedition, later known as simply "the Mordee", were originally a group of humans who travelled to the planet Mordee in the hopes of establishing a colony there. (PROSE: Doctor Who and the Face of Evil) The Fourth Doctor was aware that the expedition followed the Great Breakout of the year 5000. (TV: The Invisible Enemy)

After their arrival on the planet, their supercomputer broke down. Eventually, the Doctor came to the world and attempted to help them repair their computer. Unbeknownst to him, the computer had already evolved into a living being, Xoanon, and in making the repairs the Doctor caused it to take on his own personality. During the generations that followed, Xoanan became a deity to the people of the expedition, and they split into two tribes, the Tesh and the Sevateem. (TV: The Face of Evil)

Behind the scenes

 * In The Face of Evil and its novelisation, the Fourth Doctor referred to the colonists of the Mordee expedition as "the Mordee". The Discontinuity Guide's entry for The Face of Evil, reprinted on the BBC's official website, acknowledged the ambiguity of the Doctor's dialogue and suggests "Mordee" could refer to the ship or a human ethnic group. Later stories such as Theatre of War and Disassembled made it clear that Mordee was the name of the planet.